mahogany vs brick red

mahogany and brick red both are nouns.

Word	Noun	Adjective	Verb	Adverb
mahogany	Yes	No	No	No
brick red	Yes	No	No	No

As nouns, brick red is a hyponym of mahogany; that is, brick red is a word with a more specific, narrower meaning than mahogany:

Other hyponyms of mahogany include copper, copper color, Indian red.

mahogany (noun)	brick red (noun)
a shade of brown with a tinge of red	a bright reddish-brown color
any of various tropical timber trees of the family Meliaceae especially the genus Swietinia valued for their hard yellowish- to reddish-brown wood that is readily worked and takes a high polish
wood of any of various mahogany trees; much used for cabinetwork and furniture