Change is good—though sometimes it can throw you for a loop. This year, just when we were sure that the photographers and stylists behind our pictures had captured 2003's 50 Most Beautiful People at their freshest, a few of our youngest picks decided to make some radical changes. Perhaps to determine once and for all whether blondes really do have more fun—or maybe to test-drive a new look before her upcoming summer concert tour with Justin Timberlake
—pop diva Christina Aguilera
, 22, dyed her long platinum hair jet black. "I'm always experimenting," she says. "I like to take chances and be daring and different." The next week, Britney Spears
, 21, followed suit by trading her golden locks for a clipped bob closer to her original brunette roots (familiar to those who caught her as a tyke back in the early '90s on The Mickey Mouse Club
or Star Search
). "We'd been talking about making a big change for a while," explains her stylist Kevin Mancuso. "She's growing up, so this is a natural progression. It's hot and dramatic, hard and edgy." If all this tress stress (which got plenty of press) wasn't enough, two days later, former towhead Mary-Kate Olsen
joined Aguilera and Spears on the dark side, sporting a color described by her L.A. colorist Lorri Goddard-Clark as "milk chocolate with some caramel-honey highlights." Meanwhile, her twin sister Ashley had already gone in the opposite direction—blonder—and lopped off a full 10 inches. "It was sort of an impulse thing. Sixteen-year-old girls like short ponytails now," explains Ashley's haircutter Corey Powell. Says Goddard-Clark of the Full House
alums: "They're just having an adventure right now for themselves. It's a perfect time to have some fun." Fair enough, but blonde or not, you don't have to be a freewheeling teen or twentysomething to hear spring's irresistible call for renewal. Take a look at all 50 fabulous faces in full bloom.