umber vs chromatic

umber is a noun but chromatic is not a noun.

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

umber (noun)	chromatic (noun)
a medium brown to dark-brown color
an earth pigment

umber (adjective)	chromatic (adjective)
of the color of any of various natural brown earth pigments	being or having or characterized by hue
	based on a scale consisting of 12 semitones
	able to refract light without spectral color separation