chocolate vs burnt umber

chocolate and burnt umber both are nouns.

Word	Noun	Adjective	Verb	Adverb
chocolate	Yes	No	No	No
burnt umber	Yes	No	No	No

As nouns, chocolate and burnt umber are synonyms defined as:

Other synonyms of chocolate include coffee, deep brown, umber.

chocolate (noun)	burnt umber (noun)
a medium brown to dark-brown color	a medium brown to dark-brown color
a food made from roasted ground cacao beans	dark brown pigment obtained by heating umber
a beverage made from cocoa powder and milk and sugar; usually drunk hot