reddish blue vs violet

reddish blue and violet both are nouns.

Word	Noun	Adjective	Verb	Adverb
reddish blue	Yes	No	No	No
violet	Yes	Yes	No	No

As nouns, reddish blue and violet are synonyms defined as:

reddish blue and violet: a variable color that lies beyond blue in the spectrum

reddish blue (noun)	violet (noun)
a variable color that lies beyond blue in the spectrum	a variable color that lies beyond blue in the spectrum
	any of numerous low-growing violas with small flowers

reddish blue (adjective)	violet (adjective)
	of a color intermediate between red and blue