Effect of filters upon object color naming.

Color constancy refers to the phenomenon that the perceived colors of objects are largely unaltered by changes in the illuminant or by viewing through colored filters. Deviations from perfect constancy, induced by filters similar to ophthalmic tints, were investigated in this study. Munsell color chips were forced-choice categorized into R, Y, G, or B. This accurately located the boundaries between these colors on the chip color circle. Testing was performed through 23 different adaptive conditions and chromaticity shifts created by filters. The technique simulates real world situations in which the chromaticity of the objects and the adaptation of the observer both change. Generally, color constancy held quite well. The boundaries between the four colors shifted for some filters, indicating some deviation from perfect constancy. Red filters resulted in more color chips appearing red, blue and green filters resulted in more chips appearing blue, and filters along the Planckian locus resulted in more chips appearing green.