ASTM D 2244-05 Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates

American Society for Testing and Materials (ASTM). Current edition approved Oct. 1, 2005. Published November 2005. Originally approved in 1964. Last previous edition approved in 2002 as D 2244 – 02. 10 p. 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 D 4086 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).