olive-grey vs olive-gray

olive-grey and olive-gray both are adjectives.

Word	Noun	Adjective	Verb	Adverb
olive-grey	No	Yes	No	No
olive-gray	No	Yes	No	No

As adjectives, olive-grey and olive-gray are synonyms defined as:

olive-grey (adjective)	olive-gray (adjective)
of grey tinged with olive	of grey tinged with olive