Britney Spears: Rainbow Hair at iHeartRadio Music Festival!

Britney Spears and host Ryan Seacrest speak onstage during the 2012 iHeartRadio Music Festival at the MGM Grand Garden Arena on Friday (September 21) in Las Vegas.

The 30-year-old singer was spotted with pink and blue dye in her hair for the festival!

PHOTOS: Check out the latest pics of Britney Spears

Ryan tweeted during the festival, “How the hell does @gwenstefani keep her abs so tight?!?? #iheartradio.”

The day before, Britney was spotted leaving an Old Navy store with some shopping bags in Los Angeles.

FYI: Britney is wearing Charlotte Olympia shoes.

10+ pictures inside of Britney Spears and Ryan Seacrest at the iHeartRadio Music Fest…