Properties and Applications: Bright blue. Deep purple or celadon powder. Soluble in hot water and cold water for blue, soluble in ethanol also to blue. The strong sulfuric acid to red light brown, for yellow to green after diluted, and then into a blue. The dye solution to join sodium hydroxide deep red light brown precipitation. Used for silk, wool dyeing, also used in bamboo, wood, printing paper and ordinary paper shading, is used to make organic pigments and solvent dye.