yellow green vs Paris green

yellow green and Paris green both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellow green	Yes	No	No	No
Paris green	Yes	No	No	No

As nouns, yellow green and Paris green are synonyms defined as:

Other synonyms of yellow green include chartreuse, pea green, yellowish green.

yellow green (noun)	Paris green (noun)
a shade of green tinged with yellow	a shade of green tinged with yellow
	a toxic double salt of copper arsenate and copper acetate