brownish-red vs maroon

brownish-red is not a noun while maroon is a noun.

Word	Noun	Adjective	Verb	Adverb
brownish-red	No	Yes	No	No
maroon	Yes	Yes	Yes	No

As adjectives, brownish-red and maroon are synonyms defined as:

brownish-red (noun)	maroon (noun)
	an exploding firework used as a warning signal
	a dark purplish-red to dark brownish-red color
	a person who is stranded (as on an island)

brownish-red (adjective)	maroon (adjective)
of dark brownish to purplish red	of dark brownish to purplish red

brownish-red (verb)	maroon (verb)
	leave stranded on a desert island without resources
	leave stranded or isolated with little hope of rescue