Scaling of color sensation by magnitude estimation: a contribution to opponent-colors theory

Saturation and hue perceived in monochromatic stimuli and in light mixtures were scaled psychophysically by a direct magnitude estimation method. The colors were of aperture mode and were presented against a dark background. As a result opponent-colors functions were obtained which show the hue sensations produced by the lights of the visible spectrum (under the observing conditions used). Compared to the opponent-colors functions of Hurwich and Jameson, obtained by a cancellation technique, the subjective hue sensation differed significantly. It may be concluded that these cancellation functions describe an earlier, probably a retinal level of data processing, while our results may be regarded as a description of the output of the color vision system.