pigment
/ˈpɪgmənt; `pɪɡmənt/ n
1 [U, C] colouring matter used for making dyes, paint, etc 颜料
pigment in powder form 颜料粉
mix pigment with oil 把颜料与油混合
They used only natural pigments to dye the wool. 他们只用天然颜料染毛.
2 [U] colouring matter occurring naturally in the skin, hair, etc of living beings 色素.