Objectives Although tongue diagnosis is one of major diagnostic methods in east Asian traditional medicine, the standard of normal tongue color have not established. So we tried to suggest the method to establish the standard of normal tongue color range and the pilot data about the normal range. Materials and methods: 22 precedent study papers that presented the numerical data of normal (light red) tongue color were analyzed. At the same time, 46 adult people tongue color data were also collected and analyzed. Results Precedent studies showed remarkable fluctuations of the range of normal tongue color. Collected tongue color data of the 46 people showed mean Hue value 2 and standard deviation 14 in HSB system. Additionally, 3 ways of standard establishment for normal tongue color were suggested. Conclusion We suggest statistical method as a reasonable method for tongue color standard establishment and $2{pm}14$ as a reference Hue value for normal tongue color.