basic colour vs basic color

basic colour and basic color both are nouns.

Word	Noun	Adjective	Verb	Adverb
basic colour	Yes	No	No	No
basic color	Yes	No	No	No

As nouns, basic colour and basic color are synonyms defined as:

basic colour and basic color: a dye that is considered to be a base because the chromophore is part of a positive ion

Other synonyms of basic colour include basic dye.

basic colour (noun)	basic color (noun)
a dye that is considered to be a base because the chromophore is part of a positive ion	a dye that is considered to be a base because the chromophore is part of a positive ion