Micro arc oxidation coloring technology can endow the ceramic coating of Mg-Li alloy with specific hue，absorptivity and emissivity．Based on CIE colorimetric system，lambda950 ultraviolet visible near infrared spectrophotometer is used to measure the reflectance of objects．Then，Matlab software is used to quantify the parameters of object color including its 1931CIE chromaticity coordinates，lightness L* ，chromaticity a* 、b*，color difference ΔE* ，corresponding reflectivity curve and 1931cie chromaticity map．The results show that the color of micro arc oxidation thermal control coating can be described objectively and quantitatively by the principle of chromaticity． By establishing the relationship between hue and thermal control performance，the technology can be used to evaluate the thermal control performance of coatings．