Beautiful cat, and he's already proved his value as a member of the family by locating a mouse for you! You thought he was just hiding back there, and he was really working, earning his keep.
We had an all white cat once upon a time, named Azriel... also known as Flying Windows (computer geek joke) and Spaz... awesome cat as far as cats go. Lot of different meanings for Azrael but the most commonly known is the Angel of Death... Christian, Islamic (sort of), Hebrew, and Sikhism all have a variant of Azrael. most would peg that as a black cat name, so there's sarcasm points for him being white... but we ARE quite odd so take that with a grain...
Salt would work come to think of it... white and all... or Chlorine... Clorox...
If you want to go Mythos... I like Chakra myself, though Athena also springs to mind...