roan vs colourful

roan is a noun but colourful is not a noun.

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

roan (noun)	colourful (noun)
a horse having a brownish coat thickly sprinkled with white or gray
a soft sheepskin leather that is colored and finished to resemble morocco; used in bookbinding

roan (adjective)	colourful (adjective)
(used of especially horses) having a brownish coat thickly sprinkled with white or grey	having much or varied color
	striking in variety and interest
	having color or a certain color; sometimes used in combination