In the fierce market competition, the shelf visual impact of product packaging serves as a key factor in attracting consumers' attention. This study aims to explore the specific effects and mechanism of action of the complementary color strategy, a specific color approach, in enhancing the shelf visual impact of packaging based on the theories of color science and visual psychology. The process involves a comparative analysis of representative packaging cases on the market to explain the principle of the strong visual contrast produced by complementary colors, summarize the application strategies and differential performances of complementary colors in actual design, and construct a simple evaluation model to measure their visual effectiveness. The research conclusion indicates that the scientific application of complementary colors can significantly enhance the visibility and recognizability of packaging in a complex shelf environment, but it is necessary to pay attention to the harmony of color area ratio and lightness and purity to avoid visual discomfort.