Abstract

Color perception is categorical. Although many words for describing colors have been invented and used, there are only eleven basic color terms that are unambiguously employed to describe more than a million discriminably different colors. The 424 samples of the OSA Uniform Color Scales set are intended to sample 3-D subjective color space uniformly. A given distance in this space is, therefore, intended to represent the same number of discriminable steps of color difference, whatever the starting point or direction of measurement. Each basic color term describes a region of subjective color space, with variable exactness rather than a point. Using systematic monolexemic color naming of the OSA samples, we have confirmed the special status of the basic colors and have determined the locations of their centroids and the extents of overlapping regions in standard conditions. The method, which has the dual advantages of requiring no training of subjects or use of comparison stimuli, has been used successfully to examine color constancy, color rendering, color blindness, cultural differences, and color perception in very young children.

© 1988 Optical Society of America