Show silver / gray hair!

He's got him some silver hair

It hasn't been properly drawn/depicted yet, but they're described as having hair 'the color and texture of graphite'

It'd dyed, but hey that's silver hair with blue highlights!

he lost all hair color at the ripe age of 20 and never stopped being salty about it

hee hoo peanut

Foxy grandpa comin' through!

Grayish, but with a pearly tinge~

my silent man

angry fish girl

Atizoku here has silver hair....
Other characters of mine who also have gray/silver hair mostly have it due to old age... but.
They are: William and Henrik and Silas.