purplish-brown vs purple-brown

purplish-brown and purple-brown both are adjectives.

Word	Noun	Adjective	Verb	Adverb
purplish-brown	No	Yes	No	No
purple-brown	No	Yes	No	No

As adjectives, purplish-brown and purple-brown are synonyms defined as:

purplish-brown (adjective)	purple-brown (adjective)
of brown tinged with purple	of brown tinged with purple