ABSTRACTIn a previous paper a procedure was outlined for locating the red, green, and blue fundamental colors on a color mixture diagram. This makes it possible to derive the red, green, and blue response curves from the mixture data and the luminous efficiency curve. Curves were derived in a similar way for dichromats and compared to those for normal observers. In this paper, the study has been extended to include anomalous trichromats. In normal observers, tritanopes, and deuteranomalous subjects, the red response curve has two peaks, one at the red end and one at the blue end. The red response can be analyzed into long wave and short wave components. The short wave component is missing in deuteranopes and in the protanomalous observer investigated in this study. The data based on the one protanomal point to the possibility that the long wave component of the red response of the protanomal is similar to that of the normal but reduced in magnitude. In the deuteranomal, the green response is similar to that of a normal but reduced in magnitude.