Despite its importance and generality, the aesthetic dimension of mental experience has received little empirical study. I will describe three current projects that measure aesthetic preferences for spatial and color composition. Our results show that people consistently prefer for a single object in a rectangular frame to be positioned at or near the center of the frame (the center bias) and to face toward the center of the frame (the inward bias), and weakly prefer it to face to the right (the rightward bias). Related experiments on people's judgments of the goodness of fit for small probe shapes at various positions and orientations within a rectangular frame support the same biases, with striking evidence for the role of symmetry and balance in spatial composition. In the color domain, preferences for color combinations are well predicted by people's rated preference for the individual colors and for their ratings of the harmony of the pair. Contradicting many color theorists in the art world, complementary colors are not seen as harmonious. However, colors are judged individually as most pleasing against highly contrastive backgrounds. The results show that visual aesthetic science is a new and exciting topic within cognitive science that can shed new light on the nature of our mental representations of the visible world.