Multidimensional Ratio Scaling Analysis of Perceived Color Relations

The present study is designed to provide information relevant to the development of a uniform color scale and to investigate the relations between multidimensional scales.Two previous multidimensional successive intervals studies gave results at variance with both classical notions of color relations and implications of other more limited multidimensional studies.In this study a multidimensional-triads, ratio-judgment experiment was carried out using a set of color chips with ten normal subjects and four subjects with defective color vision. The data were analyzed separately for each individual and also for the ten normal subjects combined. The results for all the normal subjects were highly similar and were generally very close to that given by the Munsell notation.The results for the color-deficient subjects departed from those of the normal subjects in having a shortened red–green axis and in having more than two dimensions. The added dimensions appear to be due to an underestimation of big distances, particularly in the red–green direction.A direct comparison was made of the interpoint-distance estimates obtained from the multidimensional-triads ratio judgments and those obtained from an earlier multidimensional successive-intervals experiment. The ratio results were logarithmically related to the successive-intervals results. The fact that no bias was observed in the results of the triads-ratio judgments suggests that this procedure is the more appropriate technique for scaling color relations.