Coloured glass is solid sol in essence, different heavy metal ions and glass raw materials are mixed and melted, can be made into different color glass.
If MnO2(manganese oxide) is added, it is purple. CoO, Co2O3(oxide of cobalt) burned to a fuchsia color; FeO(ferrous oxide), K2Cr2O7(potassium bichromate) were burnt to green; CdS(cadmium sulfide), Fe2O3(iron oxide burned yellow; AuCl3(aluminium trichloride) and Cu2O(cuprous oxide) are burnt to red. The mixture of CuO(copper oxide), MnO2(manganese dioxide), CoO(cobalt oxide) and Fe3O4(iron oxide) are burnt to black; CaF2(calcium fluoride) and SnO2(tin oxide) are burnt to milky white. The amount of coloring dose, melting time and melting temperature will affect the color depth to different degrees.
Colored glass can absorb solar visible light and weaken the intensity of sunlight. When absorbing solar light, glass increases its own temperature and is prone to thermal expansion and cracking.