1.1 This test method is used for the instrumental measurement of the degree of yellowness (or change of degree of yellowness) under daylight illumination of homogeneous, nonfluorescent, nearly-colorless transparent or nearly-white translucent or opaque plastics. The measurement is made on pellets and based on tristimulus values obtained with a spectrophotometer or colorimeter. 1.2 This test method is applicable to the color analysis of plastic pellets. It is possible that each material will have unique characteristics that determine the color values. 1.3 This procedure outlines a method to determine color measurements, such as Yellowness Index (YI), CIE X, Y, Z, and Hunter L, a, b, or CIE L*, a*, b*. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 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. NOTE 1—This standard and ISO 17223 address the same subject matter but differ in technical content. 1.6 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.