coloured vs negro

coloured is a noun but negro is not a noun.

Word	Noun	Adjective	Verb	Adverb
coloured	Yes	Yes	No	No
negro	No	Yes	No	No

As adjectives, coloured and negro are synonyms defined as:

Other synonyms of coloured include colored.

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

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