Relationship between color of cobalt based blue pigments and lime glazes fired at 1250 ℃ under oxidation atmosphere and its blue color was obtained using Kubelka-Munk absorption data and CIELAB L, a, b system. Four glazes were prepared by Seger formulations of 0.35 KNaO, 0.65 CaO, xAl2O3, ySiO2, (x=0.35, 0.40, 0.45, 0.5, y=4.5). The influence of the glazes and zircon oxide contents on the apparent color were observed because of the Al2O3 to SiO2 raios in the lime glazes. Blue coloring of glaze was by mixing four kinds of cobalt-zircon based inorganic pigments. The apparent color of cobalt-zircon based pigments was analyzed spectroscopically. The color changing of the cobalt-zircon pigments in the lime glazes depends on the zircon oxide and alumina contents.