Katy Perry Dyes Her Hair Blue After Russell Brand Split

 Eric Berlanger/Splash News Online

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.

PHOTOS: Stars' rainbow hair colors

"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."

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.

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.

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!