I think it looks fine. Don't worry about it. No one will ever look at his hair anyway, and it will be a good memory. Kids are so precious and cute at that age no matter what.

Wait until they are teenagers .... my step-daughter's school pics this year are wonderful, simply beautiful ... except for her huge silver eyebrow ring. It's seriously the first thing you notice. And my son bleached his hair for his freshman school pics, and it had grown out a bit. So in his school pics he has an inch of white hair topping an inch of dark brown hair. LOL