A lot of actresses dye their hair. Cameron Diaz comes to mind.
Typically, however, we're looking at a blonde going brunette. Or vice versa. It's a rare case when a beautiful brown-haired star trades in her dark locks for ... pink. But Rachel McAdams has dared to go where few others ever have.
Now that she's (possibly) engaged to Ryan Gosling, perhaps the Wedding Crashers actress simply doesn't care about her looks anymore. Or perhaps she's aware that a face like that goes with any hair color.
Either way, we're on the McAdams bandwagon. She's everything that Anna Nicole Smith is not.