Let $G=(V,E)$ be a simple graph. A partition of $V(G)$ into independent,externally equitable sets is called externally equitable proper color partition of $G$ or externally equitable proper coloring of $G$. The minimum cardinality of an externally equitable proper coloring of $G$ is called externally equitable chromatic number of $G$ and is denoted by $\chi_{ee}(G)$. Since $\Pi=\{\{u_1\},\{u_2\},\cdots,\{u_n\}\}$ where $V(G)=\{u_1,u_2,\cdots,u_n\}$ is an externally equitable proper coloring of $G$, externally equitable proper color partition exists in any graph $G$. In this paper, this new parameter is introduced and studied.