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Webster 1913 Edition

[Gr. [GREEK] color +

-gen

(Biol.)

Vegetable coloring matter other than green; chromule.

(Chem.)

Any colored compound, supposed to contain one or more chromophores.

chromogen ‎(plural chromogens)

(chemistry) Any substance that lacks colour, but can be converted into a pigment or dye.
(biology) A strongly pigmented organelle or organism.