biased vs coloured

biased is not a noun while coloured is a noun.

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

As adjectives, biased and coloured are synonyms defined as:

Other synonyms of biased include colored, one-sided, slanted.

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

biased (adjective)	coloured (adjective)
favoring one person or side over another	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