pig·ment 
(pĭgmənt)
(pĭgmənt)n.
1. A substance used as coloring.
2. Dry coloring matter, usually an insoluble powder, to be mixed with water, oil, or another base to produce paint and similar products.
3. A substance, such as chlorophyll or melanin, that produces a characteristic color in plant or animal tissue.
tr.v. pig·ment·ed, pig·ment·ing, pig·ments
To color with pigment.
[Middle English, spice, red dye, from Latin pigmentum, from pingere, to paint; see peig- in the Appendix of Indo-European roots.]
pigmen·tar′y (pĭgmən-tĕr′ē) adj.