chroma vs chromatic

chroma is a noun but chromatic is not a noun.

Word	Noun	Adjective	Verb	Adverb
chroma	Yes	No	No	No
chromatic	No	Yes	No	No

chroma (noun)	chromatic (noun)
chromatic purity: freedom from dilution with white and hence vivid in hue

chroma (adjective)	chromatic (adjective)
	being or having or characterized by hue
	based on a scale consisting of 12 semitones
	able to refract light without spectral color separation