I was curious about a Movie that was also a book called the Peanut Butter incedent, were A boy's hair turns white because of something he has seen.

Nope his hair falls out because his cat slept on his head. His friend makes some sort of conncoction with peanut butter, and they put it on, and his hair won't stop growing! It's a movie from Australia I believe.
THe movie with the hair turning white due to seeing a ghost, could be "The people under the Stairs"