Saving the best for last! Britney Spears was the final celebrity to arrive at Elton John's annual AIDS Foundation Academy Awards viewing party at the Pacific Design Center in West Hollywood Feb. 24. The 31-year-old pop star made quite an impression on the red carpet, debuting a new brunette hair color and wearing a plunging Michael Cinco Couture dress.

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The "Scream & Shout" singer completed her look with De Grisogono jewelry and Saint Laurent shoes. Spears attended the star-studded soiree with her longtime manager, Larry Rudolph, and an unidentified girlfriend. (Other famous attendees included Miley Cyrus, Ryan Kwanten, Kim Kardashian, Chad Michael Murray, Heidi Klum, Chris Brown, Emma Roberts, Ian Somerhalder, Nicki Minaj and Jim Carrey.)

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"Britney seemed anxious to see who was going to be the special guest performer," a partygoer tells Us Weekly. "She was smiling and stayed fixated on the stage." Scottish newcomer Emeli Sande wowed the crowd when she sang "Heaven" "Next to Me" and "Clown."

Spears, who mingled with John and his partner David Furnish, "seemed content people watching," the partygoer says of the single mother of two, who announced her split with fiance Jason Trawick in January.

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Since its inception, John's annual viewing party and auction has raised nearly $34 million in support of healthcare initiatives providing direct treatment, care and support services for people living with HIV/AIDS.

This article originally appeared on Britney Spears Goes Brunette, Debuts New Hair Color at Elton John's Oscars Party