Color is one of the most expressive visual language in painting art. For watercolor painting, the encounter of "water " and "color" is not only the essential stipulation of its media characteristics, but also the core source of its aesthetic charm. Watercolor painting was introduced into China from Britain. After more than a hundred years of development, it has formed an artistic form with different regional characteristics. Hunan watercolor painting is unique in the field of Chinese watercolor art with the color characteristics of "clear and implicit". From the perspective of color language, this paper selects the representative works of the older generation of painters such as Huang Tieshan and Yin Baokang, as well as the backbones such as Liu Yongjian and Chen Feihu, to sort out and study the construction path and aesthetic characteristics of the color language of Hunan watercolor painting from experience to standardization, analyze the formation background and development context of its color language, convey the unique humanistic feelings and the flavor of the times of Hunan watercolor, and provide theoretical basis and practical inspiration with regional characteristics for the diversified development of Chinese watercolor painting.