umber vs brown

umber and brown both are nouns.

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

As nouns, brown is a hypernym of umber; that is, brown is a word with a broader meaning than umber:

Other hypernyms of umber include brownness.

umber (noun)	brown (noun)
a medium brown to dark-brown color	an orange of low brightness and saturation
an earth pigment

umber (adjective)	brown (adjective)
of the color of any of various natural brown earth pigments	(of skin) deeply suntanned
	of a color similar to that of wood or earth

umber (verb)	brown (verb)
	fry in a pan until it changes color
	make brown in color