purpleness vs purple

purpleness and purple both are nouns.

Word	Noun	Adjective	Verb	Adverb
purpleness	Yes	No	No	No
purple	Yes	Yes	Yes	No

As nouns, purpleness and purple are synonyms defined as:

purpleness (noun)	purple (noun)
a color between red and blue	(Roman Catholic Church) official dress of a cardinal; so named after the Tyrial purple color of the robes
	a color between red and blue
	(in ancient Rome) position of imperial status

purpleness (adjective)	purple (adjective)
	of a color intermediate between red and blue
	belonging to or befitting a supreme ruler
	excessively elaborate or showily expressed

purpleness (verb)	purple (verb)
	color purple
	become purple