Abstract
The color appearance of 24 colored objects were measured by the elementary color naming under ten different illumination of LED light, D65, red, yellow, green, and blue. The apparent colors of eleven objects to cover hues were plotted on a polar diagram used in the opponent colors theory. Under the D65 light all eleven objects gave large amount of chromaticness from 60 to 80 % making a large round contour on the diagram. A similar round contour was maintained for the most of colored illuminations but for the illuminations of which chromaticity points were almost on the spectral locus of u’v’ diagram the contour shrank and shifted toward the illumination color to indicate poor color constancy. A new index of the constancy was introduced.
