Abstract: Color, classified as warm and cool colors, impacts consumers’ product selection. How the warm and cool dimensions of colors in polychromatic pictures impact consumers’ behavior in e-commerce platforms remains unexplored. This research examines the influences of warm and cool color combinations on consumers’ liking using polychromatic stimuli in a digital reading context using empirical evidence from over 200000 exposures to 423 books. As a result, warm and cool colors (vs. neutral colors) can enhance the click-through rate, and the romance theme of novels can enhance the positive effect to consumers of warm colors (vs. neutral colors). This research extends the findings using monochromatic stimuli and indicates a theme-based visual-product attribute congruence that enhances consumers’ trial-reading choice on the digital reading platform.