primary colour vs British spelling

primary colour and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
primary colour	Yes	No	No	No
British spelling	Yes	No	No	No

primary colour (noun)	British spelling (noun)
any of three colors from which all others can be obtained by mixing	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')