Incredibles movie

Hi!

I am curious what people think.... So in The Incredibles, Bob (Mr. Incredible) is blonde, and his wife (Elastigirl, forgot the first name lol) is a redhead... How does Violet (their daughter) have black hair?

How do you think this happened?

 

I'm guessing that Elistigirl cheated.... xD idk if that's what you're thinking as well or not lol

 

Thanks for ruining my childhood, now I can never look at the incredibles the same way