coloured vs dun-coloured

coloured is a noun but dun-coloured is not a noun.

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

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

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