oxford grey vs charcoal gray

oxford grey and charcoal gray both are nouns.

Word	Noun	Adjective	Verb	Adverb
oxford grey	Yes	No	No	No
charcoal gray	Yes	No	No	No

As nouns, oxford grey and charcoal gray are synonyms defined as:

Other synonyms of oxford grey include charcoal, charcoal grey, oxford gray.

oxford grey (noun)	charcoal gray (noun)
a very dark grey color	a very dark grey color