By StyleWatch
Updated June 07, 2010 02:00 PM

Gregg DeGuire/MTV/PictureGroup; Jeff Kravitz/FilmMagic; Charley Gallay/WireImage

Bright blue hair was the only constant among Katy Perry’s trio of wardrobe switcheroos at the MTV Movie Awards last night, but each look channeled “California Gurls” – which just happens to be the title of her newest hit song. Perry hit the red carpet in a semi-nude, super-short and strategically bedazzled Zuhair Murad dress before taking the stage in sequined short-shorts and a cleavage-friendly retro bikini top to perform her latest hit, then slipped into a skintight Hervé Léger dress with an even more revealing neckline for the rest of the show. Of her final frock of the night, Perry told PEOPLE “I definitely couldn’t perform in it, because then I would be giving away way too much!” For her performance, Perry decided to channel the lyrics of her song. “I had to represent “California Gurls” by wearing Daisy Dukes and a bikini on top – California Girls aren’t just all naked!” So what defines a “California Gurl”? “We are talking about girls who are just fine, fresh, fierce and have an inner confidence that comes out of them and they are always down to earth, always ready to party and they have a little sun-kissed tan.” As for the blue hair, which she also sported at the Kids Choice Awards in March and on her new album cover, Perry said “I am going to be Smurfette one day.” Perry thinks her final look of the night was the one that fiancé Russell Brand favored most. “He likes boobs, so let’s just say he wants me to keep it on!” –Scott Huver