The Oscar-nominated actress-cum-singer abandoned her dark, punk rock tresses for a bright blue, two-toned haircut at the Los Angeles premiere of The Switch on Monday night. Lewis has always been the capricious type, and her hairstyle is no exception. From her jailbait bangs in Cape Fear, to her unwashed, blonde SoCal locks in Old School, Lewis has always taken liberties with her look. With a new rock band, The Romantiques, on tour with The Pretenders, and several films in the pipeline, Lewis has decided to turn a new page. "I have a whole other rock 'n' roll life," she told People of her surprising red carpet 'do. "We have been doing a van tour all over the states and in Canada so I literally just arrived yesterday." Chris Pizzello / AP Photo Sporting almost as many wild hair colors as evil exes, Ramona Flowers (played by Mary Elizabeth Winstead) lights up screen and the title character's life in the recent hit Scott Pilgrim vs. The World. The vixen dons combat boots, fingerless gloves, and is so terribly spontaneous, she admits to changing her hair color "every week-and-a-half." But Winstead admitted, "The blue is my favorite," in an interview with Crave Online. "I don't think most of us are impulsive enough or brave enough to change radically colors every week and a half like Ramona does, but yeah…I think I'm constantly changing it up," the actress added. And, her hair was so enviable that Pilgrim's spurned ex-girlfriend, Knives Chau (played by Ellen Wong), tried to emulate the Ramona look. She screwed up, however, and only dyed half her hair blue, proving once and for all that there can only be one Ramona Flowers. Courtesy of Universal Pictures Granted, it's just a wig, but pop star Katy Perry got blue in her sexy, Candyland-inspired music video for the biggest hit of the summer, "California Gurls." But Perry is no stranger to hair transformation. She once sported a short, messy, dirty blonde 'do as gospel singer Katy Hudson, which is her given name before she changed it to her mother's maiden name, Perry, due to confusion with the actress. Then, to capture the emo, vixen look, Perry dyed her hair black for a music video for her then-boyfriend Travis McCoy's band, Gym Class Heroes. Today, she's a full-fledged pop star, engaged to comedic actor Russell Brand, and, at the 2010 MTV Movie Awards, made her presence known in a sparkly (and revealing) Zuhair Murad dress and bright blue hair. If it was all just practice for her upcoming part in The Smurfs' big screen adaptation, we'll find out soon enough. Chris Pizzello / AP Photo Born Mario Armando Lavandeira, Jr., Perez Hilton, the self-proclaimed "Queen of All Media" showed off a royal shade of blue at the Logo's Third Annual NewNowNext Awards in June 2010. This page boy look-- reminiscent of a navy take on Javier Bardem's look in No Country For Old Men-- helped Hilton make a statement. The wig matched the indigo suit he wore to present pop star and former American Idol judge Paula Abdul with the "Always Next, Forever Now" award. We wonder if she straight up told Hilton what she thought of his baby blue 'do? Katy Winn / AP Photo Before she became a designer and a fashion icon in her own right, Gwen Stefani was better known as the punk-singing, ska-dancing lead singer of No Doubt. And as the only woman in a group of California dudes, Stefani had to make her presence known. At the MTV Movie Awards in 1998, L.A.M.B.'s leading lady channeled her inner Harajuku girl with this futuristic ensemble, complete with blue locks. "She's gone platinum, she's gone pink, she's gone fuchsia," People style director Susan Kaufman said of Stefani's ever-changing coiffure. "That's what makes her so fun." Paul Smith, Featureflash / Retna Kate Hudson's typically hippie style took an detour towards the rocker route for her role in the 2009 romantic comedy Bride Wars. The movie centers on the fall out after a clerical glitch causes the weddings of Hudson's character and her best friend's (played by Anne Hathaway) to be booked on the same day at New York's famed Plaza Hotel. What should be their respective stories of marital bliss soon become a bitchy battle. In one instance, Hathaway's character taints Hudson's highlight color with something a bit more sapphire and a bit less honey, as she requests. "It's blue!" she exclaims of the look upon the reveal. "I have blue hair!" Not every bride dares to be quite that different on her special day. Pacific Coast News Though he's best known for his role in the heart-wrenching Holocaust film The Pianist, actor Adrien Brody showed up a decidedly lighter side last May when at a screening of The Brothers Bloom with a curious smattering of blue highlights embedded in his long hair. While the New York Post speculated that Brody's look was inspired by American Idol glam rocker Adam Lambert, Brody later said that he'd gotten the streaks to give him an edge in a celebrity racing tournament. "I figured the blue would give me a little extra racing stripes," he told the Post. AP Photo Audiences accustomed to seeing Kate Winslet in prim period films such as Iris and Sense & Sensibility were treated to quite a shock when the actress starred in the quirky 2004 film Eternal Sunshine of the Spotless Mind. Playing brash, free-spirited Clementine opposite Jim Carrey, Winslet donned a number of vibrant hair colors, though it was her blue look that graced the film's promotional images. Winslet says she would have been happy to dye her hair, but she ended up using wigs instead because the film was shot of out sequence. "Literally some days I would start with red, and then by lunch time I'd be blue," Winslet told AboutFilm.com. Everett Collection It's a shame that Playing By Heart didn't meet much success at the box office, robbing moviegoers of a chance to see Cruel Intentions heartthrob Ryan Phillippe romancing Angelina Jolie with a head full of smoking cerulean hair. Though their cinematic pairing may not have earned them any style awards—they both played Los Angeles club-goers, with Jolie sporting red locks as synthetic-looking as Phillippe's blue ones—the movie did make one lasting impression on the actor. Ten years later, Ryan told Howard Stern that those sex scenes were "probably" the hottest of his career. Seemingly there's something hot about the cool shade. Everett Collection As one of the most successful fashion designers working today, Marc Jacobs sure knows how stay on the cutting edge of style—but that may not explain his blue hair. "I suppose you could say I'm having a midlife crisis," Jacobs, who was 44 at the time, told W magazine shortly before he was spotted with a close-cropped royal blue coif. Hairstylist to the stars Jordan Blackmore has taken credit for the style, saying he offered to dye Jacobs' hair when he heard that the designer was considering a bold change. "I'd done a lot of blue," Blackmore told W magazine. "Marc loved it." Sara De Boer / Retna Ltd. Blue hair is no fad for Marge, the matriarch of the Simpsons clan, who's been rocking her sky-high blue beehive for 21 seasons and counting. The distinctive look is said to be a cross between The Bride of Frankenstein and creator Matt Groening's own mother Margaret, but the real Ms. Groening denies the link. "It was never blue," she once told the Seattle Times of her own hairstyle. Regardless, Simpson's hair has been a cultural landmark despite one dirty little secret: Marge has been dying her hair for years, one Simpsons episode revealed. "She's been gray as a mule since she was seventeen," according to her husband Homer. Blue is definitely an upgrade. Courtesy of Fox