vividness vs colourful

vividness is a noun but colourful is not a noun.

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

vividness (noun)	colourful (noun)
chromatic purity: freedom from dilution with white and hence vivid in hue
interest and variety and intensity

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