Coloring matters can be divided into two categories- organic coloring matter and inorganic coloring matter. There is one kind of coloring organic compounds called organic dyestuff because it can dye the fibrous and other materials fresh and fast by suitable ways. This organic dyestuff can be soluble in water and some other solvents, or can be transformed to some soluble solution, or can dye the fibrous materials through some processes. Another kind of coloring organic compounds can't be soluble in water and other solvents, but can dye the materials with small granularity factors, it's called organic pigments. In the contrary, some metallic oxide/sulfide like Cds(chrome yellow), HgS(vermilion)..etc, these are inorganic coloring matters because they can't be soluble in water but still can dye the materials.