Color glass is adding colorant to ordinary glass, such as adding MnO2 to purple; CoO, Co2O3 to purplish red; FeO, K2Cr2O7 to green; CdS, Fe2O3, SB2S3, to yellow; AuCl3, Cu2O to red; CuO , MnO2, CoO, Fe3O4 mixture fired black; CaF2, SnO2 fired milky white. The amount of colorant, the melting time and the melting temperature will affect the depth of the fired color to varying degrees. The use of colloidal colorants, such as gold, silver, copper, selenium, sulfur, etc., causes extremely small particles to be suspended in the glass body to color the glass.