Why are the bald eagle head feathers white?

I have a theory. I've noticed the easiest way to tell a bird of prey apart from non predatory birds is by the tail shape and head. If the head and tail are white it's very difficult for the prey to recognize the eagle as a predator against the sky. I've noticed pigeons where I live don't mind the turkey buzzards flying over head, but as soon as a hawk in the air they immediately bolt. If all you can see of a bald eagle in the sky is the wing shape, it is easy to think the large bird may just be a goose, duck or buzzard.