colloquialism vs white-haired

colloquialism is a noun but white-haired is not a noun.

Word	Noun	Adjective	Verb	Adverb
colloquialism	Yes	No	No	No
white-haired	No	Yes	No	No

colloquialism (noun)	white-haired (noun)
a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech

colloquialism (adjective)	white-haired (adjective)
	favorite
	showing characteristics of age, especially having grey or white hair