I don't think he will go gray because his legs are very light in color.
Usually with a gray they will have darker points......more like an adult horse color.
The goggle indicator doesn't always work. My foal (now a 2 yr old) is turning gray and he never had goggles. Only recently does he even have a single white eyelash.
My guess is bay (or brown). I know the mane/tail doesn't look black but neither did the mane/tail on my foal for the longest time and they are black now. For the longest time I thought he was liver chestnut.