WireImage 1 / 17

Things are looking bright for "X Factor" judge Britney Spears -- literally!

The "Oops! ... I Did It Again" pop star, 30, rocked pink and blue hair extensions when she joined Ryan Seacrest, 37, on stage during the iHeartRadio Music Festival in Las Vegas Sept. 21. Spears showed off her trim figure in a black minidress by David Lerner and glitter platform heels by Charlotte Olympia.

PHOTOS: Britney Spears' sexiest tour costumes ever

"Hello, Las Vegas!" a beaming Spears said onstage. "You know why I love this festival. It's packed with every kind of music fan." (Performers included Jason Aldean, Rihanna and Bon Jovi, among others.)

VIDEO: Why Britney Spears says the "X Factor judges" "ganged up" on her

Spears added, "This is Vegas, baby, so we've got the world's most insane deejays here to keep the party going all night long."

Though Spears only recently decided to experiment with a more colorful 'do, fellow "X Factor" judge Demi Lovato, 20, rocked rainbow hairstyles throughout the show's nationwide talent auditions this summer. The two musicians joined veteran judges Simon Cowell, 52, and L.A. Reid, 56, on the FOX hit, which airs Wednesdays and Thursdays at 8 p.m. EST on FOX.

Tell Us: Do you like Britney Spears' rainbow hair extensions?

This article originally appeared on Usmagazine.com: Britney Spears Gets Rainbow Hair Extensions: Love It or Hate It?


Stars Misbehaving: What Happens in Vegas ...

Is Britney Dragging Her Feet Over Wedding No. 3?

Celebs Who Date Behind-the-Scenesters