Color confusion tests employing Munsell paper stimuli were given to 5 cebus monkeys, including 1 female. Ss were trained to discriminate on the basis of hue. Since Cebus1 spectral sensitivity may differ from human''s, lightness values of Munsell pairs were varied for each combination of wavelengths. Results provided no evidence of dichromacy. Assuming the "Anomalous trichromats are intermediate in their ability to make chromatic distinctions between normal and dichromatic observers of the protanopic, deuteranopic, and tritanopic types, respectively [Judd, 1951, p. 827]," results support the hypothesis that individual Cebus may have defective color vision of the deuteranomalous as well as the protanomalous variety.