Davy's grey vs Davy's gray

Davy's grey and Davy's gray both are nouns.

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

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

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

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