First off, I am not a breeder and don't know a whole lot about genetics. My only qualification to even comment is that I had a foal last year out of my gray mare, and researched everything I could find about "gray" because I was also eager to know what color my colt was and if he would turn gray. (And he is!)
Well, my guess is that your baby is not gray, based only on the fact that he has light points. Apparently most gray foals are born with dark legs. But, in the photo where he is the youngest, he almost looks black, so that sort of throws things off for me.
But anyway, most gray foals have dark legs while most bay and chestnut foals have fawn colored legs.
They also say to look for stray white hairs, even a single one, especially on the face and around the eyes. That didn't prove a good clue with my baby however, as I could not find a single white hair on him when he was born (outside his white markings of course). My baby started getting his first scattered white hairs with his winter coat.
So take it with a grain of salt, because I honestly have no idea. But I'm guessing non-gray just based on the light colored legs.
PS. Here is Zane after he was born. He is a bay-going-gray. And the second photo is a "normal" bay foal.