The purpose of this study was analyzing the features of architectural colors in Hongseong-gun and proposing environmental color design for regional identity color. According to the analysis, Hongseong's base colors are YR of low hue value and grayish tone colors. But a lot of signs and outdoor billboards mar the beauty of the environmental color. So it is more important to solve the problems as well as new environmental color design. The results are as follows; 1) Naepo Color Palette of 2009 Chungnam Public Design Master Plan would be an accepted principal for the contextual landscape image of Chungnam in macro perspective. 2) Outdoor signboards must be controlled and improved for the harmony of the buildings dominant colors. 3) Roof color would arrange R or grayish of deep tone colors those are similar balance of Hongseong base color YR, and gate color would have clear principles of the order such as chromatic or brightness contrast in housing. 4) Forming of future oriented image of Hongseong need to be considered first as to whether it is harmonious tones with existing local base colors.