We investigated cultural differences between U.S. and Japanese color preferences and the ecological factors that might influence them. Japanese and U.S. color preferences have both similarities and differences. Complex gender differences were also evident that did not conform to previously reported effects. Palmer and Schloss's weighted affective valence estimate procedure was used to test the Ecological Valence Theory's prediction that within-culture WAVE-preference correlations should be higher than between-culture WAVE-preference correlations. The results supported several, but not all, predictions. In the second (...) experiment, we tested color preferences of Japanese–U.S. multicultural participants who could read and speak both Japanese and English. Multicultural color preferences were intermediate between U.S. and Japanese preferences, consistent with the hypothesis that culturally specific personal experiences during one's lifetime influence color preferences. (shrink)