Australian spelling vs poster colour

Australian spelling and poster colour both are nouns.

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

Australian spelling (noun)	poster colour (noun)
English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')	pigment mixed with water-soluble glutinous materials such as size and egg yolk