Gwen Stefani's platinum blonde hair has been a key part of her signature style since her early No Doubt days. Despite the near-constant bleach, somehow, the musician's hair has always managed to look like it's in its healthiest state. And while she has occasionally dipped into bright colors like pink and blue, her icy hair remains consistent. For a performance on the season finale of The Voice, however, Stefani looked like Cruella De Vil's long-lost twin with her new black-and-white ponytail. The musician shared a carousel on Instagram featuring a selfie and two short videos showing off ...