dun-colored vs coloured

dun-colored is not a noun while coloured is a noun.

Word	Noun	Adjective	Verb	Adverb
dun-colored	No	Yes	No	No
coloured	Yes	Yes	No	No

dun-colored (noun)	coloured (noun)
	a United States term for Blacks that is now considered offensive

dun-colored (adjective)	coloured (adjective)
having a dun color	having color or a certain color; sometimes used in combination
	(used of color) artificially produced; not natural
	having skin rich in melanin pigments;
	favoring one person or side over another