brown-gray vs brownish-grey

brown-gray and brownish-grey both are adjectives.

Word	Noun	Adjective	Verb	Adverb
brown-gray	No	Yes	No	No
brownish-grey	No	Yes	No	No

As adjectives, brown-gray and brownish-grey are synonyms defined as:

Other synonyms of brown-gray include brown-grey, brownish-gray.

brown-gray (adjective)	brownish-grey (adjective)
of grey tinged with brown	of grey tinged with brown