Katherine Heigl Is Back to Blonde

Credit: Ben Dome/Jeff Steinberg/ PacificCoastNews.com

Katherine Heigl is back to blonde -- temporarily, anyway.

The actress, 31, donned a blonde wig while shooting additional scenes for her upcoming comedy Killers Wednesday in Los Angeles.

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The same day, Heigl finally confirmed she was leaving the ABC medical drama after six seasons.

"We just finalized our agreement," she told Entertainment Weekly. "Everyone had been working really hard to find an amicable and gracious way of letting go and moving on. It's sad, but it's what I wanted."

Heigl told UsMagazine.com that she dyed her hair dark brunette to play the main character in the film adaptation of Janet Evanovich's novel One for the Money -- a wisecracking new Jersey detective named Stephanie Plum.

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"She is a very specific kind of girl, so I just wanted to show the legion of fans that I will be your vision of Stephanie Plum," she said. "It's important. I hate when my favorite books are made into films and they are just not what you expect."

She admitted she was still getting used to the new look.

"I was pretty shocked at first... I was like, 'wow, it's dark, that's not just brown, that's black.' It took me a good day and a half to totally embrace it," she said.

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But now?

"I love it. It's fun. I feel a bit different even though I don't act any different. I say all the same stupid things -- I just look different," she continued.