reddish-purple vs red-purple

reddish-purple and red-purple both are adjectives.

Word	Noun	Adjective	Verb	Adverb
reddish-purple	No	Yes	No	No
red-purple	No	Yes	No	No

As adjectives, reddish-purple and red-purple are synonyms defined as:

reddish-purple (adjective)	red-purple (adjective)
of purple tinged with red	of purple tinged with red