Davy's grey vs steel grey

Davy's grey and steel grey both are nouns.

Word	Noun	Adjective	Verb	Adverb
Davy's grey	Yes	No	No	No
steel grey	Yes	No	No	No

As nouns, Davy's grey and steel grey are synonyms defined as:

Other synonyms of Davy's grey include Davy's gray, iron blue, steel gray.

Davy's grey (noun)	steel grey (noun)
slightly purplish or bluish dark grey	slightly purplish or bluish dark grey