E12.04 - Color and Appearance Analysis

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design, and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice covers standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔE00 units (6) are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. This color-difference equation is appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color difference by listing the three instrumentally determined components of the color difference.  
5.4 Selection of color tolerances based on instrumental values should be carefully correlated with a visual appraisal of the acceptability of differences in hue, lig...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99o color difference formula given in DIN 6176  (4), or the CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Many competent measurement laboratories comply with accepted quality system requirements such as ISO 9001, QS 9000, or ISO 17025. When using standard test methods, the measurement results should agree with those from other similar laboratories within the combined uncertainty limits of the laboratories’ measurement systems. It is for this reason that quality system requirements demand that a statement of the uncertainty of the test results accompany every test result.  
5.2 Preparation of uncertainty estimates is a requirement for laboratory certification under ISO 17025. This practice describes the procedures by which such uncertainty estimates may be calculated.
SCOPE
1.1 This practice describes a protocol to be utilized by measurement laboratories for estimating and reporting the uncertainty of a measurement result when the result is derived from a measurand that has been obtained by spectrophotometry.  
1.2 This practice is specifically limited to the reporting of uncertainty of color measurement results that are reported as color-differences in ΔE format, even though the measurement itself may be reported in other units such as percent reflectance or transmittance.  
1.3 The procedures defined here are not intended to be applicable to national standardizing laboratories or transfer laboratories.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.  
5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.
SCOPE
1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.  
1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X10, Y10, Z10 and x10. y10 for the CIE 1964 supplementary standard observer.  
1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants. Weight sets are included for tristimulus integration of nine standard or recommended CIE LED illuminants combined with the two standard CIE observers.  
1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.  
1.5 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The gray scale grade GSC is useful to evaluate the color difference of any pair of colors that have been subjected to a test whose severity of result is nominated by color difference of the treated member to the untreated member. This includes, but is not limited to, scrub tests, exterior exposures, crocking tests, blocking tests, certain abrasion tests, and color transfer tests.  
5.2 A major advantage of the instrumental method of obtaining gray scale grades is that under the visual method substantial screening and training of the operators in visual color assessment is required. No such burden is placed on the operators in this instrumental method.  
5.3 The method is usually not used for staining tests which have their own gray scale for staining.
SCOPE
1.1 Test Method D2616 describes a painted gray scale and the procedure to be used in the visual evaluation of color differences on non-self-luminous materials by comparison to this scale. This practice provides an alternative method of obtaining a similarly valued result by an instrumental method.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard, except that the test results of this test method are converted by the calculations to an arbitrary visual scale defined by Test Method D2616, whose units are called GSC (Gray Scale for Change in Color).  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 The options available in methods for the measurement of color or color-difference are many. These involve choices in: (1) specimens, (2) geometric and spectral properties of instruments, (3) calibration bases for standards used, (4) procedure for sample handling including conditioning, (5) procedure for taking data, and (6) equations for converting instrumental data to final results. Once the measurements have been made, it is essential to document what has been done for the purpose of interlaboratory comparisons, or for future use. A sample form is provided in Fig. 1 to record identifying information applicable to any instrumental method of color or color-difference measurement.  
4.2 Refer to Guide E179, Practices E991, E1164, E1345, E1708, E1767, E2152, and E2194 and Test Methods D5386, D6166, E1247, E1331, E1347, E1348, and E1349, for specific details of measurements.
SCOPE
1.1 This practice covers the documentation of instrumental measurement of color or color difference for current communication or for future reference. The practice is applicable to instrumental measurements of materials where color is seen by reflected, transmitted or emitted light and any combinations of one or more of these processes. The practice is recommended for documentation of methodology in interlaboratory color-measurement programs.  
1.2 Providing an adequate identification of an instrumental measure of color or color-difference involves documenting the metadata necessary for archiving and future use of the measurement data collected. The metadata can be divided in five parts:  
1.2.1 Nature and source of available samples and the form of specimens actually measured,  
1.2.2 Instrumental conditions of measurement, including instrument geometrical and spectral conditions of measurement,  
1.2.3 Standards used,  
1.2.4 Data acquisition procedure, and  
1.2.5 Color scales employed.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This practice is intended to provide a method that will yield uniformity of calculations used in making, matching, or controlling colors of objects. This uniformity is accomplished by providing a method for calculation of weighting factors for tristimulus integration consistent with the methods utilized to obtain the weighting factors for common illuminant-observer combinations contained in Practice E308.  
5.2 This practice should be utilized by persons desiring to calculate a set of weighting factors for tristimulus integration who have custom source, or illuminant spectral power distributions, or custom observer response functions.
SCOPE
1.1 This practice describes the method to be used for calculating tables of weighting factors for tristimulus integration using custom spectral power distributions of illuminants or sources, or custom color-matching functions.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Failure to make such a rectification introduces differences from the true value of the spectrum of about 0.02 to 0.4 ΔE*ab units. All users are required to make a rectification of such bandpass differences. It is especially incumbent upon writers of computer programs whose function it is to acquire such spectra from instruments to see that a competent rectification is implemented in the program before any additional processing of the spectrum, or calculations involving the spectrum are accomplished, or before the spectrum is made available to a user.  
5.2 Legacy measuring systems are explicitly exempted from any requirements for retrofitting of hardware or software and may continue to utilize previously accepted methods of making the bandwidth rectification.
SCOPE
1.1 This standard outlines the methods that can be used to deconvolve, at least partially, the spectral bandpass differences of raw spectral data acquired by abridged spectrophotometry. Such differences are introduced because the spectral passband must be of significant bandwidth to allow sufficient energy to reach the detector. On the other hand, the spectral data that should be reported is that of a virtual 1-nm bandwidth spectrum in order to be useful in the CIE method of tristimulus integration which involves 1-nm summation.  
1.2 The standard establishes practices for whether, when, and how a bandpass rectification should be made to any reflectance or transmittance spectrum acquired by abridged spectrophotometry.  
1.3 It is applicable where the shape of the passband is triangular and the bandwidth is equal to the measurement interval between passbands. Information is provided in Section 7 for users when that condition is not satisfactorily met.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The rejection of materials due to color is a common and expensive occurrence, and it is useful for a customer and producer to set color specifications with an associated tolerance before the transaction. This guide discusses the concept and details the ASTM standards to be used in the process.
SCOPE
1.1 This guide leads the user through a process for establishing color specifications, including the target color and allowable tolerances. It refers to the appropriate ASTM standards that more thoroughly describe each step of the process beginning with expectations, encompassing caveats within the process and finally concluding with reporting.  
1.2 This guide does not suggest numerical values for tolerances. These values must be agreed upon by the parties involved.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This practice should be used only to compare specimens of the same material and same general appearance. For example, a series of specimens to be compared should have generally similar gloss, texture, and (if not opaque) thickness, and translucency.  
5.2 For yellowness measurement, this practice is limited to specimens having dominant wavelength in the range 570 to 580 nm, or Munsell hue approximately 2.5GY to 2.5Y. For whiteness measurement, this practice is limited to specimens having Munsell value greater than 8.3 (CIE Y greater than 65) and Munsell chroma no greater than 0.5 for B hues, 0.8 for Y hues, and 0.3 for all other hues (see 3.3.1).  
5.3 The combination of measurement and calculation leading to indices of yellowness or whiteness is a psychophysical process, that is, the procedures specified are designed to provide numbers correlating with visual estimates made under specified typical observing conditions. Because visual observing conditions can vary widely, users should compare calculated indices with visual estimates to ensure applicability. Some standards addressing the visual estimation of color and color difference are Practices D1535, D1729, E1360, and E1541, and Guide E1499.  
5.4 This practice does not cover the preparation of specimens, a procedure that may affect significantly the quantities measured. In general, specimens should be prepared and presented for measurement in the manner that is standard for the test being performed. Select enough specimens or specimen areas to provide an average result that is representative of each sample to be tested. See Practice E1345.
SCOPE
1.1 This practice provides numbers that correlate with visual ratings of yellowness or whiteness of white and near-white or colorless object-color specimens, viewed in daylight by an observer with normal color vision. White textiles, paints, and plastics are a few of the materials that can be described by the indices of yellowness or whiteness calculated by this practice.  
1.2 For a complete analysis of object colors, by a specified observer and under a specified illuminant, use of three parameters is required. For near-white specimens, however, it is often useful to calculate single-number scales of yellowness or whiteness. This practice provides recommended equations for such scales and discusses their derivations and uses, and limits to their applicability (see also Ref (1)2).  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This practice should be used by manufacturers of color-measuring instruments and developers of software when the transmission of color and appearance data is desired between instruments or computers and where ASCII files are the desired method of transfer.  
5.2 The method of transmission may be via direct connection, modem, or the transfer of electronic media, for example, by floppy disk transfer.  
5.3 The practice lends itself to the transmission of either a single record of data or multiple record files.  
5.4 Examples of files generated in this practice are contained in Fig. X1.1 and Fig. X2.1 of Appendix X1 and Appendix X2.
SCOPE
1.1 This practice covers procedures to be used in the electronic exchange of color and appearance data between users, by either modem or the physical transfer of electronic media. It is intended for use by manufacturers of color-measuring instruments and developers of software so that any instrument may acquire data for its use that may have been measured on an instrument of another manufacturer, at another place, or at another time.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This practice should be used whenever measured color-scale or color-difference-scale values are to be compared to an established tolerance. In this way it can be demonstrated quantitatively that the sampling and measurement procedures are adequate to allow an unambiguous decision as to whether or not the mean results are within tolerance.  
5.2 This practice is based on portions of SAE J 1545, as it applies to painted or plastic automotive parts. It is generally applicable to object colors in various materials. Textured materials, such as textiles, may require special consideration (see SAE J 1545 and STP 15D Manual on Presentation of Data and Control Chart Analysis5).  
5.3 While Practice E178 deals with outliers, it does not include definitions relating to the box and whisker technique. The definition of an outlier is operational and a little vague because there is still considerable disagreement about what constitutes an outlier. In any normally distributed population, there will be members that range from minus to plus infinity. Theoretically, one should include any member of the population in any sample based on estimates of the population parameters. Practically, including a member that is found far from the mean within a small sample, most members of which are found near the mean, will introduce a systematic bias into the estimate of the population parameters (mean, standard deviation, standard error). Such a bias is in direct contrast with the goal of this practice, namely, to reduce the effects of variability of measurement. For the purposes of this practice, no distinction is made between errors of sampling and members of the tails of the distribution. Practice E178 has several methods and significance tables to attempt to differentiate between these two types of extreme values.
SCOPE
1.1 Reduction of the variability associated with average color or color-difference measurements of object-color specimens is achieved by statistical analysis of the results of multiple measurements on a single specimen, or by measurement of multiple specimens, whichever is appropriate.  
1.2 This practice provides a means for the determination of the number of measurements required to reduce the variability to a predetermined fraction of the relevant color or color-difference tolerances.  
1.3 This practice is general in scope rather than specific as to instrument or material.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔE00 units (6) are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. This color-difference equation is appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color difference by listing the three instrumentally determined components of the color difference.  
5.4 Selection of color tolerances based on instrumental values should be carefully correlated with a visual appraisal of the acceptability of differences in hue, lig...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99o color difference formula given in DIN 6176  (4), or the CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔECMC or ΔE00 units are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The Hunter color difference components ΔLH, ΔaH, ΔbH, and their color difference unit ΔEH, are used by the coil coating and aluminum extrusion coating industries, as well as the customers of these users. They are, therefore, included in Appendix X1 for historical purposes and use.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color ...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1)2, CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176  (4), or the CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This practice should be used by manufacturers of color-measuring instruments and developers of software when the transmission of color and appearance data is desired between instruments or computers and where ASCII files are the desired method of transfer.  
5.2 The method of transmission may be via direct connection, modem, or the transfer of electronic media, for example, by floppy disk transfer.  
5.3 The practice lends itself to the transmission of either a single record of data or multiple record files.  
5.4 Examples of files generated in this practice are contained in Fig. X1.1 and Fig. X2.1 of Appendix X1 and Appendix X2.
SCOPE
1.1 This practice covers procedures to be used in the electronic exchange of color and appearance data between users, by either modem or the physical transfer of electronic media. It is intended for use by manufacturers of color-measuring instruments and developers of software so that any instrument may acquire data for its use that may have been measured on an instrument of another manufacturer, at another place, or at another time.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This practice should be used by manufacturers of color-measuring instruments and developers of software when the transmission of color and appearance data is desired between instruments or computers and where ASCII files are the desired method of transfer.  
5.2 The method of transmission may be via direct connection, modem, or the transfer of electronic media, for example, by floppy disk transfer.  
5.3 The practice lends itself to the transmission of either a single record of data or multiple record files.  
5.4 Examples of files generated in this practice are contained in Fig. X1.1 and Fig. X2.1 of Appendix X1 and Appendix X2.
SCOPE
1.1 This practice covers procedures to be used in the electronic exchange of color and appearance data between users, by either modem or the physical transfer of electronic media. It is intended for use by manufacturers of color-measuring instruments and developers of software so that any instrument may acquire data for its use that may have been measured on an instrument of another manufacturer, at another place, or at another time.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Many competent measurement laboratories comply with accepted quality system requirements such as ISO 9001, QS 9000, or ISO 17025. When using standard test methods, the measurement results should agree with those from other similar laboratories within the combined uncertainty limits of the laboratories’ measurement systems. It is for this reason that quality system requirements demand that a statement of the uncertainty of the test results accompany every test result.  
5.2 Preparation of uncertainty estimates is a requirement for laboratory certification under ISO 17025. This practice describes the procedures by which such uncertainty estimates may be calculated.
SCOPE
1.1 This practice describes a protocol to be utilized by measurement laboratories for estimating and reporting the uncertainty of a measurement result when the result is derived from a measurand that has been obtained by spectrophotometry.  
1.2 This practice is specifically limited to the reporting of uncertainty of color measurement results that are reported as color-differences in ΔE format, even though the measurement itself may be reported in other units such as percent reflectance or transmittance.  
1.3 The procedures defined here are not intended to be applicable to national standardizing laboratories or transfer laboratories.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.  
5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.
SCOPE
1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.  
1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X10, Y10, Z10 and x10. y10 for the CIE 1964 supplementary standard observer.  
1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants.  
1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.  
1.5 Procedures are included for cases in which the spectral data are, and those in which they are not, corrected for bandpass dependence. For the uncorrected cases, it is assumed that the spectral bandpass of the instrument used to obtain the data was approximately equal to the measurement interval and was triangular in shape. These choices are believed to correspond to the most widely used industrial practice.  
1.6 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The gray scale grade GSC is useful to evaluate the color difference of any pair of colors that have been subjected to a test whose severity of result is nominated by color difference of the treated member to the untreated member. This includes, but is not limited to, scrub tests, exterior exposures, crocking tests, blocking tests, certain abrasion tests, and color transfer tests.  
5.2 A major advantage of the instrumental method of obtaining gray scale grades is that under the visual method substantial screening and training of the operators in visual color assessment is required. No such burden is placed on the operators in this instrumental method.  
5.3 The method is usually not used for staining tests which have their own gray scale for staining.
SCOPE
1.1 Test Method D2616 describes a painted gray scale and the procedure to be used in the visual evaluation of color differences on non-self-luminous materials by comparison to this scale. This practice provides an alternative method of obtaining a similarly valued result by an instrumental method.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard, except that the test results of this test method are converted by the calculations to an arbitrary visual scale defined by Test Method D2616, whose units are called GSC (Gray Scale for Change in Color).  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 The options available in methods for the measurement of color or color-difference are many. These involve choices in: (1) specimens, (2) geometric and spectral properties of instruments, (3) calibration bases for standards used, (4) procedure for sample handling including conditioning, (5) procedure for taking data, and (6) equations for converting instrumental data to final results. Once the measurements have been made, it is essential to document what has been done for the purpose of interlaboratory comparisons, or for future use. A sample form is provided in Fig. 1 to record identifying information applicable to any instrumental method of color or color-difference measurement.
FIG. 1 Sample Report Form    
Metadata for Color or Color Difference Measurement of Specimens  
4.2 Refer to Guide E179, Practices E991, E1164, E1345, E1708, E1767, E2152, and E2194 and Test Methods D5386, D6166, E1247, E1331, E1347, E1348, and E1349, for specific details of measurements.
SCOPE
1.1 This practice covers the documentation of instrumental measurement of color or color difference for current communication or for future reference. The practice is applicable to instrumental measurements of materials where color is seen by reflected, transmitted or emitted light and any combinations of one or more of these processes. The practice is recommended for documentation of methodology in interlaboratory color-measurement programs.  
1.2 Providing an adequate identification of an instrumental measure of color or color-difference involves documenting the metadata necessary for archiving and future use of the measurement data collected. The metadata can be divided in five parts:  
1.2.1 Nature and source of available samples and the form of specimens actually measured,  
1.2.2 Instrumental conditions of measurement, including instrument geometrical and spectral conditions of measurement,  
1.2.3 Standards used,  
1.2.4 Data acquisition procedure, and  
1.2.5 Color scales employed.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.  
5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.
SCOPE
1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.  
1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X10, Y10, Z10 and x10. y10 for the CIE 1964 supplementary standard observer.  
1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants.  
1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.  
1.5 Procedures are included for cases in which the spectral data are, and those in which they are not, corrected for bandpass dependence. For the uncorrected cases, it is assumed that the spectral bandpass of the instrument used to obtain the data was approximately equal to the measurement interval and was triangular in shape. These choices are believed to correspond to the most widely used industrial practice.  
1.6 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The rejection of materials due to color is a common and expensive occurrence, and it is useful for a customer and producer to set color specifications with an associated tolerance before the transaction. This guide discusses the concept and details the ASTM standards to be used in the process.
SCOPE
1.1 This guide leads the user through a process for establishing color specifications, including the target color and allowable tolerances. It refers to the appropriate ASTM standards that more thoroughly describe each step of the process beginning with expectations, encompassing caveats within the process and finally concluding with reporting.  
1.2 This guide does not suggest numerical values for tolerances. These values must be agreed upon by the parties involved.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This practice is intended to provide a method that will yield uniformity of calculations used in making, matching, or controlling colors of objects. This uniformity is accomplished by providing a method for calculation of weighting factors for tristimulus integration consistent with the methods utilized to obtain the weighting factors for common illuminant-observer combinations contained in Practice E308.  
5.2 This practice should be utilized by persons desiring to calculate a set of weighting factors for tristimulus integration who have custom source, or illuminant spectral power distributions, or custom observer response functions.
SCOPE
1.1 This practice describes the method to be used for calculating tables of weighting factors for tristimulus integration using custom spectral power distributions of illuminants or sources, or custom color-matching functions.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to its use.

SIGNIFICANCE AND USE
5.1 Failure to make such a rectification introduces differences from the true value of the spectrum of about 0.02 to 0.4 ΔE*ab units. All users are required to make a rectification of such bandpass differences. It is especially incumbent upon writers of computer programs whose function it is to acquire such spectra from instruments to see that a competent rectification is implemented in the program before any additional processing of the spectrum, or calculations involving the spectrum are accomplished, or before the spectrum is made available to a user.  
5.2 Legacy measuring systems are explicitly exempted from any requirements for retrofitting of hardware or software and may continue to utilize previously accepted methods of making the bandwidth rectification.
SCOPE
1.1 This standard outlines the methods that can be used to deconvolve, at least partially, the spectral bandpass differences of raw spectral data acquired by abridged spectrophotometry. Such differences are introduced because the spectral passband must be of significant bandwidth to allow sufficient energy to reach the detector. On the other hand, the spectral data that should be reported is that of a virtual 1-nm bandwidth spectrum in order to be useful in the CIE method of tristimulus integration which involves 1-nm summation.  
1.2 The standard establishes practices for whether, when, and how a bandpass rectification should be made to any reflectance or transmittance spectrum acquired by abridged spectrophotometry.  
1.3 It is applicable where the shape of the passband is triangular and the bandwidth is equal to the measurement interval between passbands. Information is provided in Section 7 for users when that condition is not satisfactorily met.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The rejection of materials due to color is a common and expensive occurrence, and it is useful for a customer and producer to set color specifications with an associated tolerance before the transaction. This guide discusses the concept and details the ASTM standards to be used in the process.
SCOPE
1.1 This guide leads the user through a process for establishing color specifications, including the target color and allowable tolerances. It refers to the appropriate ASTM standards that more thoroughly describe each step of the process beginning with expectations, encompassing caveats within the process and finally concluding with reporting.  
1.2 This guide does not suggest numerical values for tolerances. These values must be agreed upon by the parties involved.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔECMC or ΔE00 units are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The Hunter color difference components ΔLH, ΔaH, ΔbH, and their color difference unit ΔEH, are used by the coil coating and aluminum extrusion coating industries, as well as the customers of these users. They are, therefore, included in Appendix X1 for historical purposes and use.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color ...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

SIGNIFICANCE AND USE
5.1 The gray scale grade GSC is useful to evaluate the color difference of any pair of colors that have been subjected to a test whose severity of result is nominated by color difference of the treated member to the untreated member. This includes, but is not limited to, scrub tests, exterior exposures, crocking tests, blocking tests, certain abrasion tests, and color transfer tests.  
5.2 A major advantage of the instrumental method of obtaining gray scale grades is that under the visual method substantial screening and training of the operators in visual color assessment is required. No such burden is placed on the operators in this instrumental method.  
5.3 The method is usually not used for staining tests which have their own gray scale for staining.
SCOPE
1.1 Test Method D2616 describes a painted gray scale and the procedure to be used in the visual evaluation of color differences on non-self-luminous materials by comparison to this scale. This practice provides an alternative method of obtaining a similarly valued result by an instrumental method.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard, except that the test results of this test method are converted by the calculations to an arbitrary visual scale defined by Test Method D2616, whose units are called GSC (Gray Scale for Change in Color).  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The gray scale grade GSC is useful to evaluate the color difference of any pair of colors that have been subjected to a destructive test whose severity of result is nominated by color difference of the treated member to the untreated member. This includes, but is not limited to, scrub tests, exterior exposures, crocking tests, blocking tests, certain abrasion tests, and color transfer tests.  
5.2 A major advantage of the instrumental method of obtaining gray scale grades is that under the visual method substantial screening and training of the operators in visual color assessment is required. No such burden is placed on the operators in this instrumental method.  
5.3 The method is usually not used for staining tests which have their own gray scale for staining.
SCOPE
1.1 Test Method D2616 describes a painted gray scale and the procedure to be used in the visual evaluation of color differences on non-self-luminous materials by comparison to this scale. This test method provides an alternative method of obtaining a similarly valued result by an instrumental method.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard, except that the test results of this test method are converted by the calculations to an arbitrary visual scale defined by Test Method D2616, whose units are called GSC (Gray Scale for Change in Color).  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔECMC or ΔE00 units are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The Hunter color difference components ΔLH, ΔaH, ΔbH, and their color difference unit ΔEH, are used by the coil coating and aluminum extrusion coating industries, as well as the customers of these users. They are, therefore, included in Appendix X1 for historical purposes and use.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color ...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

SIGNIFICANCE AND USE
5.1 Failure to make such a rectification introduces differences from the true value of the spectrum of about 0.02 to 0.4 ΔE*ab units. All users are required to make a rectification of such bandpass differences. It is especially incumbent upon writers of computer programs whose function it is to acquire such spectra from instruments to see that a competent rectification is implemented in the program before any additional processing of the spectrum, or calculations involving the spectrum are accomplished, or before the spectrum is made available to a user.  
5.2 Legacy measuring systems are explicitly exempted from any requirements for retrofitting of hardware or software and may continue to utilize previously accepted methods of making the bandwidth rectification.
SCOPE
1.1 This standard outlines the methods that can be used to deconvolve, at least partially, the spectral bandpass differences of raw spectral data acquired by abridged spectrophotometry. Such differences are introduced because the spectral passband must be of significant bandwidth to allow sufficient energy to reach the detector. On the other hand, the spectral data that should be being reported is that of a virtual 1-nm bandwidth spectrum in order to be useful in the CIE method of tristimulus integration which involves 1-nm summation.  
1.2 The standard establishes practices for whether, when, and how a bandpass rectification should be made to any reflectance or transmittance spectrum acquired by abridged spectrophotometry.  
1.3 It is applicable where the shape of the passband is triangular and the bandwidth is equal to the measurement interval between passbands. Information is provided in Section 7 for users when that condition is not satisfactorily met.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.  
5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.
SCOPE
1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.  
1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X10, Y10, Z10 and x10. y10 for the CIE 1964 supplementary standard observer.  
1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants.  
1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.  
1.5 Procedures are included for cases in which the spectral data are, and those in which they are not, corrected for bandpass dependence. For the uncorrected cases, it is assumed that the spectral bandpass of the instrument used to obtain the data was approximately equal to the measurement interval and was triangular in shape. These choices are believed to correspond to the most widely used industrial practice.  
1.6 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This practice should be used only to compare specimens of the same material and same general appearance. For example, a series of specimens to be compared should have generally similar gloss, texture, and (if not opaque) thickness, and translucency.  
5.2 For yellowness measurement, this practice is limited to specimens having dominant wavelength in the range 570 to 580 nm, or Munsell hue approximately 2.5GY to 2.5Y. For whiteness measurement, this practice is limited to specimens having Munsell value greater than 8.3 (CIE Y greater than 65) and Munsell chroma no greater than 0.5 for B hues, 0.8 for Y hues, and 0.3 for all other hues (see 3.3.1).  
5.3 The combination of measurement and calculation leading to indices of yellowness or whiteness is a psychophysical process, that is, the procedures specified are designed to provide numbers correlating with visual estimates made under specified typical observing conditions. Because visual observing conditions can vary widely, users should compare calculated indices with visual estimates to ensure applicability. Some standards addressing the visual estimation of color and color difference are Practices D1535, D1729, E1360, and E1541, and Guide E1499.  
5.4 This practice does not cover the preparation of specimens, a procedure that may affect significantly the quantities measured. In general, specimens should be prepared and presented for measurement in the manner that is standard for the test being performed. Select enough specimens or specimen areas to provide an average result that is representative of each sample to be tested. See Practice E1345.
SCOPE
1.1 This practice provides numbers that correlate with visual ratings of yellowness or whiteness of white and near-white or colorless object-color specimens, viewed in daylight by an observer with normal color vision. White textiles, paints, and plastics are a few of the materials that can be described by the indices of yellowness or whiteness calculated by this practice.  
1.2 For a complete analysis of object colors, by a specified observer and under a specified illuminant, use of three parameters is required. For near-white specimens, however, it is often useful to calculate single-number scales of yellowness or whiteness. This practice provides recommended equations for such scales and discusses their derivations and uses, and limits to their applicability (see also Ref (1)2).  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔECMC or ΔE00 units are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The Hunter color difference components ΔLH, ΔaH, ΔbH, and their color difference unit ΔEH, are used by the coil coating and aluminum extrusion coating industries, as well as the customers of these users. They are, therefore, included in Appendix X1 for historical purposes and use.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color ...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔECMC or ΔE00 units are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The Hunter color difference components ΔLH, ΔaH, ΔbH, and their color difference unit ΔEH, are used by the coil coating and aluminum extrusion coating industries, as well as the customers of these users. They are, therefore, included in Appendix X1 for historical purposes and use.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure. It is possible to include information on the direction of a small color ...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

SIGNIFICANCE AND USE
5.1 This practice should be used only to compare specimens of the same material and same general appearance. For example, a series of specimens to be compared should have generally similar gloss, texture, and (if not opaque) thickness, and translucency.  
5.2 For yellowness measurement, this practice is limited to specimens having dominant wavelength in the range 570 to 580 nm, or Munsell hue approximately 2.5GY to 2.5Y. For whiteness measurement, this practice is limited to specimens having Munsell value greater than 8.3 (CIE Y greater than 65) and Munsell chroma no greater than 0.5 for B hues, 0.8 for Y hues, and 0.3 for all other hues (see 3.3.1).  
5.3 The combination of measurement and calculation leading to indices of yellowness or whiteness is a psychophysical process, that is, the procedures specified are designed to provide numbers correlating with visual estimates made under specified typical observing conditions. Because visual observing conditions can vary widely, users should compare calculated indices with visual estimates to ensure applicability. Some standards addressing the visual estimation of color and color difference are Practices D1535, D1729, E1360, and E1541, and Guide E1499.  
5.4 This practice does not cover the preparation of specimens, a procedure that may affect significantly the quantities measured. In general, specimens should be prepared and presented for measurement in the manner that is standard for the test being performed. Select enough specimens or specimen areas to provide an average result that is representative of each sample to be tested. See Practice E1345.
SCOPE
1.1 This practice provides numbers that correlate with visual ratings of yellowness or whiteness of white and near-white or colorless object-color specimens, viewed in daylight by an observer with normal color vision. White textiles, paints, and plastics are a few of the materials that can be described by the indices of yellowness or whiteness calculated by this practice.  
1.2 For a complete analysis of object colors, by a specified observer and under a specified illuminant, use of three parameters is required. For near-white specimens, however, it is often useful to calculate single-number scales of yellowness or whiteness. This practice provides recommended equations for such scales and discusses their derivations and uses, and limits to their applicability (see also Ref (1)2).  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This practice should be used whenever measured color-scale or color-difference-scale values are to be compared to an established tolerance. In this way it can be demonstrated quantitatively that the sampling and measurement procedures are adequate to allow an unambiguous decision as to whether or not the mean results are within tolerance.  
5.2 This practice is based on portions of SAE J 1545, as it applies to painted or plastic automotive parts. It is generally applicable to object colors in various materials. Textured materials, such as textiles, may require special consideration (see SAE J 1545 and STP 15D Manual on Presentation of Data and Control Chart Analysis5).  
5.3 While Practice E178 deals with outliers, it does not include definitions relating to the box and whisker technique. The definition of an outlier is operational and a little vague because there is still considerable disagreement about what constitutes an outlier. In any normally distributed population, there will be members that range from minus to plus infinity. Theoretically, one should include any member of the population in any sample based on estimates of the population parameters. Practically, including a member that is found far from the mean within a small sample, most members of which are found near the mean, will introduce a systematic bias into the estimate of the population parameters (mean, standard deviation, standard error). Such a bias is in direct contrast with the goal of this practice, namely, to reduce the effects of variability of measurement. For the purposes of this practice, no distinction is made between errors of sampling and members of the tails of the distribution. Practice E178 has several methods and significance tables to attempt to differentiate between these two types of extreme values.
SCOPE
1.1 Reduction of the variability associated with average color or color-difference measurements of object-color specimens is achieved by statistical analysis of the results of multiple measurements on a single specimen, or by measurement of multiple specimens, whichever is appropriate.  
1.2 This practice provides a means for the determination of the number of measurements required to reduce the variability to a predetermined fraction of the relevant color or color-difference tolerances.  
1.3 This practice is general in scope rather than specific as to instrument or material.

SIGNIFICANCE AND USE
5.1 This practice should be used by manufacturers of color-measuring instruments and developers of software when the transmission of color and appearance data is desired between instruments or computers and where ASCII files are the desired method of transfer.  
5.2 The method of transmission may be via direct connection, modem, or the transfer of electronic media, for example, by floppy disk transfer.  
5.3 The practice lends itself to the transmission of either a single record of data or multiple record files.  
5.4 Examples of files generated in this practice are contained in Fig. X1.1 and Fig. X2.1 of Appendix X1 and Appendix X2.
SCOPE
1.1 This practice covers procedures to be used in the electronic exchange of color and appearance data between users, by either modem or the physical transfer of electronic media. It is intended for use by manufacturers of color-measuring instruments and developers of software so that any instrument may acquire data for its use that may have been measured on an instrument of another manufacturer, at another place, or at another time.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 Many competent measurement laboratories comply with accepted quality system requirements such as ISO 9001, QS 9000, or ISO 17025. When using standard test methods, the measurement results should agree with those from other similar laboratories within the combined uncertainty limits of the laboratories’ measurement systems. It is for this reason that quality system requirements demand that a statement of the uncertainty of the test results accompany every test result.  
5.2 Preparation of uncertainty estimates is a requirement for laboratory certification under ISO 17025. This practice describes the procedures by which such uncertainty estimates may be calculated.
SCOPE
1.1 This practice describes a protocol to be utilized by measurement laboratories for estimating and reporting the uncertainty of a measurement result when the result is derived from a measurand that has been obtained by spectrophotometry.  
1.2 This practice is specifically limited to the reporting of uncertainty of color measurement results that are reported as color-differences in ΔE format, even though the measurement itself may be reported in other units such as percent reflectance or transmittance.  
1.3 The procedures defined here are not intended to be applicable to national standardizing laboratories or transfer laboratories.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.  
5.2 Color differences calculated in ΔECMC or ΔE00 units are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units. Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The CIELAB color-difference unit ΔE*ab is not recommended for use with color differences less than 5.0 ΔE*ab units. The Hunter color difference components ΔLH, ΔaH, ΔbH, and their color difference unit ΔEH, are used by the coil coating and aluminum extrusion coating industries, as well as the customers of these users. They are, therefore, included in Appendix X1 for historical purposes and use.  
5.3 Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standar...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1),2 CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000 color difference units (5).  
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

SIGNIFICANCE AND USE
5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.  
5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.
SCOPE
1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.  
1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X10, Y10, Z10 and x10.  y10 for the CIE 1964 supplementary standard observer.  
1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants.  
1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.  
1.5 Procedures are included for cases in which the spectral data are, and those in which they are not, corrected for bandpass dependence. For the uncorrected cases, it is assumed that the spectral bandpass of the instrument used to obtain the data was approximately equal to the measurement interval and was triangular in shape. These choices are believed to correspond to the most widely used industrial practice.  
1.6 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 Many competent measurement laboratories comply with accepted quality system requirements such as ISO 9001, QS 9000, or ISO 17025. When using standard test methods, the measurement results should agree with those from other similar laboratories within the combined uncertainty limits of the laboratories’ measurement systems. It is for this reason that quality system requirements demand that a statement of the uncertainty of the test results accompany every test result.  
5.2 Preparation of uncertainty estimates is a requirement for laboratory certification under ISO 17025. This practice describes the procedures by which such uncertainty estimates may be calculated.
SCOPE
1.1 This practice describes a protocol to be utilized by measurement laboratories for estimating and reporting the uncertainty of a measurement result when the result is derived from a measurand that has been obtained by spectrophotometry.  
1.2 This practice is specifically limited to the reporting of uncertainty of color measurement results that are reported as color-differences in ΔE format, even though the measurement itself may be reported in other units such as percent reflectance or transmittance.  
1.3 The procedures defined here are not intended to be applicable to national standardizing laboratories or transfer laboratories.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 7 on Hazards.

SIGNIFICANCE AND USE
The options available in methods for the measurement of color or color-difference are many. These involve choices in: (1) specimens, (2) geometric and spectral properties of instruments, (3) calibration bases for standards used, (4) procedure for sample handling including conditioning, (5) procedure for taking data, and (6) equations for converting instrumental data to final results. Once the measurements have been made, it is essential to document what has been done for the purpose of interlaboratory comparisons, or for future use. A sample form is provided in Fig. 1 to record identifying information applicable to any instrumental method of color or color-difference measurement.
Refer to Guide E179, Practices E991, E1164, E1345, E1708, E1767, E2152, and E2194 and Test Methods D5386, D6166, E1247, E1331, E1347, E1348, and E1349, for specific details of measurements.
Metadata for Color or Color Difference Measurement of Specimens
FIG. 1 Sample Report Form
SCOPE
1.1 This practice covers the documentation of instrumental measurement of color or color difference for current communication or for future reference. The practice is applicable to instrumental measurements of materials where color is seen by reflected, transmitted or emitted light and any combinations of one or more of these processes. The practice is recommended for documentation of methodology in interlaboratory color-measurement programs.
1.2 Providing an adequate identification of an instrumental measure of color or color-difference involves documenting the metadata necessary for archiving and future use of the measurement data collected. The metadata can be divided in five parts:
1.2.1 Nature and source of available samples and the form of specimens actually measured,
1.2.2 Instrumental conditions of measurement, including instrument geometrical and spectral conditions of measurement,  
1.2.3 Standards used,
1.2.4 Data acquisition procedure, and
1.2.5 Color scales employed.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.  
5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.
SCOPE
1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.  
1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X10, Y10, Z10 and x10.  y10 for the CIE 1964 supplementary standard observer.  
1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants.  
1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.  
1.5 Procedures are included for cases in which the spectral data are, and those in which they are not, corrected for bandpass dependence. For the uncorrected cases, it is assumed that the spectral bandpass of the instrument used to obtain the data was approximately equal to the measurement interval and was triangular in shape. These choices are believed to correspond to the most widely used industrial practice.  
1.6 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers.7 Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.  
5.2 This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.  
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
In today's commerce, instrument makers and instrument users must deal with a large array of bench-top and portable color-measuring instruments, many with different geometric and spectral characteristics. At the same time, manufacturers of colored goods are adopting quality management systems that require periodic verification of the performance of the instruments that are critical to the quality of the final product. The technology involved in optics and electro-optics has progressed greatly over the last decade. The result has been a generation of instruments that are both more affordable and higher in performance. What had been a tool for the research laboratory is now available to the retail point of sale, to manufacturing, to design and to corporate communications. New documentary standards have been published that encourage the use of colorimeters, spectrocolorimeters, and colorimetric spetrometers in applications previously dominated by visual expertise or by filter densitometers. Therefore, it is necessary to determine if an instrument is suitable to the application and to verify that an instrument or instruments are working within the required operating parameters.
This practice provides descriptions of some common instrumental parameters that relate to the way an instrument will contribute to the quality and consistency of the production of colored goods. It also describes some of the material standards required to assess the performance of a color-measuring instrument and suggests some tests and test reports to aid in verifying the performance of the instrument relative to its intended application.
SCOPE
1.1 This practice provides standard terms and procedures for describing and characterizing the performance of spectral and filter based instruments designed to measure and compute the colorimetric properties of materials and objects. It does not set the specifications but rather gives the format and process by which specifications can be determined, communicated and verified.
1.2 This practice does not describe methods that are generally applicable to visible-range spectroscopic instruments used for analytical chemistry (UV-VIS spectrophotometers). ASTM Committee E13 on Molecular Spectroscopy and Chromatography includes such procedures in standards under their jurisdiction.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.