As a core medium for early childhood literacy, picture books transcend linguistic and cultural barriers through their integrated visual storytelling artistry, earning widespread popularity among children. In this visual language, color serves as a vital medium for emotional transmission while playing an irreplaceable role in narrative progression and contextual construction. This study analyzes the color expression characteristics and thematic structural patterns of classic picture books, revealing their intrinsic connection through three pathways: emotional resonance, symbolic metaphor, and rhythmic modulation. Through case studies of "The Jungle Book" and "The Very Hungry Caterpillar", this research further demonstrates color's aesthetic and educational value in picture book narratives. The findings provide theoretical support and practical references for visual communication design in picture book creation, while offering innovative approaches to optimize early childhood reading resources.