chromatism vs pigmentation

chromatism and pigmentation both are nouns.

Word	Noun	Adjective	Verb	Adverb
chromatism	Yes	No	No	No
pigmentation	Yes	No	No	No

As nouns, pigmentation is a hypernym of chromatism; that is, pigmentation is a word with a broader meaning than chromatism:

chromatism (noun)	pigmentation (noun)
abnormal pigmentation	coloration of living tissues by pigment
hallucinatory perception of colored lights	the deposition of pigment in animals or plants or human beings