peacock blue vs aquamarine

peacock blue and aquamarine both are nouns.

Word	Noun	Adjective	Verb	Adverb
peacock blue	Yes	No	No	No
aquamarine	Yes	No	No	No

As nouns, peacock blue and aquamarine are synonyms defined as:

Other synonyms of peacock blue include aqua, cobalt blue, greenish blue, turquoise.

peacock blue (noun)	aquamarine (noun)
a shade of blue tinged with green	a shade of blue tinged with green
	a transparent variety of beryl that is blue green in color