Auron why does he look so old

[Tavrobel]

I've got grey hair, and I am not stressed, wise, or anything that constitutes anything to having grey hair whatsoever. I figured out that it is my genes that give me grey hair.

[XxSephirothxX]

Well, some people just get gray hair early. That's certainly a plausible explanation. My guess is they just wanted him to look mature, wise, and hardened, so a little gray hair was added to his character design. They might not have even chosen an age until afterwards.

[Zeromus_X]

He's also based off of a samurai character in a Kurosawa film (go figure.), though I can't remember the name of the character off-hand.. Maybe that has something to do with it?

And also,

(SPOILER)well, he is dead