mahogany-red vs red-brown

mahogany-red and red-brown both are adjectives.

Word	Noun	Adjective	Verb	Adverb
mahogany-red	No	Yes	No	No
red-brown	No	Yes	No	No

As adjectives, mahogany-red and red-brown are synonyms defined as:

Other synonyms of mahogany-red include reddish-brown.

mahogany-red (adjective)	red-brown (adjective)
of brown tinged with red	of brown tinged with red