alizarin red vs alizarin crimson

alizarin red and alizarin crimson both are nouns.

Word	Noun	Adjective	Verb	Adverb
alizarin red	Yes	No	No	No
alizarin crimson	Yes	No	No	No

As nouns, alizarin red and alizarin crimson are synonyms defined as:

alizarin red and alizarin crimson: any of various acid dyes; used for dyeing wool scarlet red

Other synonyms of alizarin red include alizarin carmine.

alizarin red (noun)	alizarin crimson (noun)
any of various acid dyes; used for dyeing wool scarlet red	any of various acid dyes; used for dyeing wool scarlet red