Predicting corresponding colors with changes in adaptation

A method is proposed for determining chromaticity coordinates of stimuli that elicit the same colors over changes in chromatic adaptation. The method uses equations derived from a recent study of the influence of chromatic adaptation on color appearance. A single set of Konig-type fundamental primaries is used, and the “red” and “green” fundamentals are altered by changes in adaptation according to a coefficient rule while, in addition, the “blue” fundamental is modified through a power transform. No ulterior information is required beyond a knowledge of the chromaticities of samples and illuminants. The method agrees well with the experimental data from which it was derived, with predictions from a number of other transformation methods, and with raw data from five independent studies of chromatic adaptation. The method thus offers utility and a reasonable compromise between generality and simplicity on the one hand and accuracy on the other.