What kind of names do you want? Like named after famous people, or named after something grey, or named something just funny and random, etc. I have a small list of them for you, they all have to do with his color:
Cinder
Foggy
Dusk
Cobweb
Granite
Hazy
Mercury
Zeus
Pheonix (because of the whole rising from the ashes thing)
Silverado
Slate
Stone
Pepper
Tinsel
I know that some of these names are kinda girly, sorry. Hope these help you out!
~chickenchick
P.S. What breed is he? Love it! So handsome.