Most Dramatic Celebrity Hair Makeovers

The Gossip Girl star went auburn in late April for her role in the upcoming film Hick. In June, Lively lightened her strands back to blond. "I love it," she told InStyle.com on her ever-changing 'do. "When I play a character I love to completely transform, and changing up my hair color is a way I feel like I can disappear behind them."

Aniston chopped her long layers into a one-length bob while promoting her film Just Go With It in February. The cut, courtesy of Aniston's longtime hairstylist and friend Chris McMillan, is the first time she has had above-the-shoulders strands since her famous Rachel shag in the '90s.

Katy Perry

went back to her blond roots in July, then revealed a new lavender hue at the VMAs in August. "It was such an exciting challenge to custom-create Katy's color for the VMAs," her colorist Rita Hazan said. "She is always willing to take risks to achieve a groundbreaking look."

The Glee actress cut her blond waves into an edgy shag in August. "It feels more like me than ever," she told InStyle.com exclusively. "I love it! I don't miss blow-drying my hair, I don't miss the maintenance, and it's just fun to switch things up."

In September, the Bridesmaids star chopped her chestnut strands into an above-the-shoulders bob with thick, arched bangs.

In June, Wood debuted her new pixie crop at the True Blood season four premiere party in Los Angeles.

Carrie Underwood debuted pitch-perfect bangs that hit just below the brow in late September.

Mother-to-be Duff lightened her tawny brown strands at the end of March.

In April, Barrymore traded her two-tone ombre for blazing red. "We had been talking about going red for a few months, and since Drew has been auburn before, we knew it would look good," her colorist Tracey Cunningham told InStyle.com exclusively. "It wasn't a spur-of-the-moment decision. When Drew changes her hair color, she really commits to it." History repeated itself in early November, when Barrymore went back to her ombre roots and snipped her strands into a long bob.

For her role as Katniss Everdeen in The Hunger Games , Lawrence switched her sunny blond for a deep brown in May.

After going platinum for her role as Gwen Stacy in The Amazing Spider-Man, Emma Stone returned to red in early June. The actress showed off her shoulder-length copper strands a preview of her film The Help.