Brittany Snow is another blonde who reached new heights of beauty by going brunette. This is one dramatic makeover, taking Snow from cutesy to couture. Once again, we're left to wonder why she would ever go back to blonde.

Yeah, yeah. We know. It was for her "Fantastic Four" character. Still, it's a great example of someone who just wasn't born to be blonde. Jessica Alba's super-brassy blonde is not just unflattering on her. It's a bad hair color period. If you're a lovely latina like Jessica, work with your natural assets. You won't go wrong. The world has enough blondes.

It's impressive how different Julia Roberts looks when she changes her hair color. This washed-out red was a major misstep. While she's been a redhead with success before, this particular shade made her look downright anemic.

When Scarlett Johansson went blonde, she went all the way. While this may not be your cup of tea, her head of hair is healthy, shiny and brassiness-free. If you're gonna go platinum blonde, this is one great way to do it.