Why do people like some colors more than others? Why do they have color preferences at all? Recent results from the Berkeley Color Project (BCP) provide intriguing answers based on people's emotional responses to diagnostically colored objects. We report preferences among 32 chromatic colors from 48 adults in the San Francisco Bay area and describe their fit to several color preference models, including ones based on cone outputs, color-emotion associations, and our own ecological valence theory (EVT). The EVT postulates that color serves an adaptive “steering” function, analogous to taste preferences, by biasing organisms to approach advantageous objects and avoid disadvantageous ones. It implies that people will tend to like colors to the extent that they like the objects that are characteristically that color, averaged over all such objects. The EVT predicts 80% of the variance in average color preference ratings from the Weighted Affective Valence Estimates (WAVEs) of correspondingly colored objects, much more variance than any of the other models. We also describe how hue preferences for single colors differ as a function of gender, expertise, culture, social institutions, and perceptual experience.