colourful vs polychrome

colourful is not a noun while polychrome is a noun.

Word	Noun	Adjective	Verb	Adverb
colourful	No	Yes	No	No
polychrome	Yes	Yes	Yes	No

colourful (noun)	polychrome (noun)
	a piece of work composed of or decorated in many colors

colourful (adjective)	polychrome (adjective)
having much or varied color	having or exhibiting many colors
striking in variety and interest
having color or a certain color; sometimes used in combination

colourful (verb)	polychrome (verb)
	color with many colors; make polychrome