off-color vs American spelling

off-color is not a noun while American spelling is a noun.

Word	Noun	Adjective	Verb	Adverb
off-color	No	Yes	No	No
American spelling	Yes	No	No	No

off-color (noun)	American spelling (noun)
	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')

off-color (adjective)	American spelling (adjective)
humorously vulgar
in violation of good taste even verging on the indecent