ivory vs off-white

ivory and off-white both are nouns.

Word	Noun	Adjective	Verb	Adverb
ivory	Yes	No	No	No
off-white	Yes	Yes	No	No

As nouns, ivory and off-white are synonyms defined as:

Other synonyms of ivory include bone, pearl.

ivory (noun)	off-white (noun)
a shade of white the color of bleached bones	a shade of white the color of bleached bones
a hard smooth ivory colored dentine that makes up most of the tusks of elephants and walruses

ivory (adjective)	off-white (adjective)
	of something having a color tending toward white