burnt sienna vs sepia

burnt sienna and sepia both are nouns.

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

As nouns, burnt sienna and sepia are synonyms defined as:

Other synonyms of burnt sienna include mahogany, reddish brown, Venetian red.

burnt sienna (noun)	sepia (noun)
a shade of brown with a tinge of red	a shade of brown with a tinge of red
a reddish-brown pigment produced by roasting sienna	rich brown pigment prepared from the ink of cuttlefishes