Standardized independent contrasts corrected for phylogenetic relatedness of female melanin- vs. carotenoid-based plumage and sexual dichromatism in melanin- vs. carotenoid-based plumage. Throat achromatic brightness and breast saturation (A: ventral comparison) are strongly correlated, as are back achromatic brightness and rump saturation (B: dorsal comparison). As female carotenoid saturation increases, female achromatic brightness decreases, resulting in a more contrasting appearance. Differences between males and females in throat achromatic brightness and breast saturation (C) and in back achromatic brightness and rump saturation (D) are strongly correlated. As dichromatism in carotenoid-based plumage increases, so does dichromatism in melanin-based plumage.