Color difference formulas: An unsatisfactory state of affairs

Color difference formulas are of considerable importance in production control of colored materials, as they offer a kind of quantitative numerical method to predict perceived differences. Current formulas are based oil various sets of empirical difference perception data established with different kinds of materials, under different evaluation conditions, and with different observer panels. The best current formulas predict the average of these perceptual data only with an accuracy of about 65%, a PF/3 value of about 35 (zero being optimal). This article argues that this is an unsatisfactory state of affairs and proposes the development of new uniformly established perceptual data and a new formula/system that predicts the visual results, statistically verified to represent the world-average observer, with an accuracy of 95%, a PF/3 value (or appropriate improved measure) of 5 or lower. Such a multiyear effort requires a solid experimental plan and a consortium supported by Government and industry to achieve its goal. (c) 2008 Wiley Periodicals, Inc.