Will my horse turn white?

Yes, your horse is a grey and white paint. So yes, he will continue to lighten up, and in all likelihood (sp?) end up "white". The colored patches will have grey skin, and the white parts will have pink skin. As mentioned, some greys become fleabitten, which looks like little flecks of color vs all "white."

I've always been told that if a percheron is going to go grey they are born with grey eyelashes, if the lashes are black the horse will stay black. If you look at the picture of the grey/white horse it's lashes are grey, look at the red/white horse it's lashes are a dark color and the horse is older and hasn't lost a lot of it's color. Maybe there is something to the theory of the grey lashes.

who needs baby powder for something that big? spray paint him...tee hee

haha i never thought of that!