pearly vs achromatic

pearly is a noun but achromatic is not a noun.

Word	Noun	Adjective	Verb	Adverb
pearly	Yes	Yes	No	No
achromatic	No	Yes	No	No

pearly (noun)	achromatic (noun)
informal terms for a human `tooth'

pearly (adjective)	achromatic (adjective)
of a white the color of pearls	having no hue