Color, as the fundamental language of the art discipline, is a key vehicle for cultivating aesthetic perception and creative practice. However, current color instruction in primary schools often deviates from children's cognitive levels, leading to "adultified" teaching in lower grades and superficial instruction in upper grades. Grounded in the laws of children's psychological development, this paper analyzes the intrinsic connections between Piaget's cognitive development theory and the staged learning tasks outlined in the new curriculum standards. In response to practical challenges such as misaligned teaching objectives, fragmented content, and single-track assessment, it proposes stage-based color teaching strategies: in Stage 1, activate aesthetic perception through game-based experiences; in Stage 2, deepen cultural understanding via contextual inquiry; and in Stage 3, enhance creative practice through thematic creation. Only by aligning with the trajectory of children's psychological development can art teaching quality be effectively improved and core competencies genuinely realized.