water-colour vs British spelling

water-colour and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
water-colour	Yes	No	No	No
British spelling	Yes	No	No	No

water-colour (noun)	British spelling (noun)
the art or technique of painting with watercolors	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')
a painting produced with watercolors
a water-base paint (with water-soluble pigments); used by artists
water-soluble pigment