achromatic color vs American spelling

achromatic color and American spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
achromatic color	Yes	No	No	No
American spelling	Yes	No	No	No

achromatic color (noun)	American spelling (noun)
a color lacking hue; white or grey or black	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')