Twenty-one subjects rated a random sequence of 144 color pairs on a categorical scale ranging from 1 (harmonizing) to 7 (clashing). Another group of 35 subjects rated each individual color on a set of semantic differential scales. The colors were also scaled objectively in terms of Munsell measures for hue, chroma, and value. The color harmony ratings were analyzed by using multidimensional scaling and invoking a weighted individual-differences Euclidean distance model. A two-dimensional solution accounted for 83.1% of the variability in the transformed data matrices. On the basis of supplementary regression analyses, it was found that hue, value (brightness), and the psychological attribute “pleasantness,” were the factors that influenced the color harmony judgments. In general, harmonious color combinations involved colors that were similar with regard to these attributes.