cyan vs bluish green

cyan and bluish green both are nouns.

Word	Noun	Adjective	Verb	Adverb
cyan	Yes	Yes	No	No
bluish green	Yes	Yes	No	No

As nouns, bluish green is a hypernym of cyan; that is, bluish green is a word with a broader meaning than cyan:

Other hypernyms of cyan include blue green, teal.

cyan (noun)	bluish green (noun)
a primary subtractive color for light; has a blue-green color	a blue-green color or pigment

cyan (adjective)	bluish green (adjective)
of the blue-green color that is a primary subtractive color of light	of a bluish shade of green