SRPS H.C8.995:2025

Standard Practice for Calculating Yellowness and Whiteness Indices from Instrumentally Measured Color Coordinates

Scope

This practice provides numbers that correlate with visual ratings of yellowness or whiteness of white and nearwhite 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. 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.