Katy Perry Dyes Her Hair Blue After Russell Brand Split

Katy Perry is still blue over her split from Russell Brand -- literally.

On Thursday, the 27-year-old pop star emerged for the first time since the British comic, 36, filed for divorce on December 30. Debuting a new blue hair color, Perry posed with a fan named Eric Berlanger on the set of an Adidas commercial in Santa Barbara, Calif.

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"It was great to see her. I met her a couple times before," Berlanger says. "I am a big fan! She was great, really nice. She seemed happy."

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Despite Perry's chipper demeanor, a source tells the new issue of Us Weekly (on stands now) that the "Firework" singer was blindsided when Brand filed divorce papers, effectively ending their 14-month marriage.

"She wants his stuff out of their house in Hollywood," an insider explains.

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Perry didn't waste any time, either: moving vans were spotted outside the couple's $6.5 million L.A. home on January 4. "She is all about moving on now," the insider tells Us.