burnt sienna vs brown

burnt sienna and brown both are nouns.

Word	Noun	Adjective	Verb	Adverb
burnt sienna	Yes	No	No	No
brown	Yes	Yes	Yes	No

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

Other hypernyms of burnt sienna include brownness.

burnt sienna (noun)	brown (noun)
a shade of brown with a tinge of red	an orange of low brightness and saturation
a reddish-brown pigment produced by roasting sienna

burnt sienna (adjective)	brown (adjective)
	(of skin) deeply suntanned
	of a color similar to that of wood or earth

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