skin colour vs Australian spelling

skin colour and Australian spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
skin colour	Yes	No	No	No
Australian spelling	Yes	No	No	No

skin colour (noun)	Australian spelling (noun)
the coloring of a person's face	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')