Boli peasant paintings are the most representative form of folk art in the Lixiahe water town region of northern Jiangsu, characterized by their vivid and distinctive color palette. This article systematically analyzes the color system of Boli peasant paintings from three perspectives: aesthetic characteristics, folkloric connotations, and contemporary transmission. It identifies three key features in the use of color: a high-purity overall tone, a decorative order marked by strong contrast, and subjective color application. The formation of this color palette is rooted in the combined influence of seasonal customs, folk notions of auspiciousness, and local handicraft traditions in the Lixiahe region. Building on this foundation, the paper further explores the cultural identity functions and preservation challenges of this color system in the contemporary context. It argues that the continuity of Boli peasant painting’s color tradition depends on the conscious preservation of the local aesthetic experiences and rural cultural psychology that underpin it.