colorist vs painter

colorist and painter both are nouns.

Word	Noun	Adjective	Verb	Adverb
colorist	Yes	No	No	No
painter	Yes	No	No	No

As nouns, painter is a hypernym of colorist; that is, painter is a word with a broader meaning than colorist:

colorist (noun)	painter (noun)
a painter able to achieve special effects with color	large American feline resembling a lion
	a line that is attached to the bow of a boat and used for tying up (as when docking or towing)
	an artist who paints
	a worker who is employed to cover objects with paint