silvery-grey vs silvery-gray

silvery-grey and silvery-gray both are adjectives.

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

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

Other synonyms of silvery-grey include silver-gray, silver-grey.

silvery-grey (adjective)	silvery-gray (adjective)
of grey resembling silver	of grey resembling silver