It may not be considered the "standard of perfection " without any grey to him, but unless you are planning on showing or breeding, it's perfectly fine. As long as he's happy and healthy you shouldn't worry about it. Do you have any other geese?
Beautiful boy! I'm pretty sure with pilgrim geese, the males are actually white...the females are the ones with the grey pattern. I'll try to find the breed information page and link it on here for you.