What is he?

Just curious if someone could explain something to me? So Echo is the palest grey like white with just a touch of grey mixed in. He has no facial markings whatsoever, his head is grey, theres no white nor yellow, and no cheek markings. The only markings he has anywhere are the two white stripes on his wings. The closest I can get to his type is a double factor dominant pastel silver whiteface, but he doesn't have a whiteface, is this because he's young? (13 weeks old) will his markings change? or is he just some really strange mutation? I was under the impression white faces had a white face even as babies...

Theres pics of Echo in my sig, he's actually lighter in colour in real life but otherwise their pretty accurate. Oh and I'm pretty sure he's a boy he chatters away continually and can already speak.