Katy Perry?s Hair, From Blonde to Pink [PHOTOS]

Katy Perry was just sporting a blonde hairdo last week, but now she's gone all pretty and pink.

Perry, 26, was spotted in Los Angeles Monday, water bottles in tow, with pink hair tied into a bun, People reports.

Just last week, the singer made a grand entrance with her blonde hair at the New York premiere of "The Smurfs," complete with a Smurfette dress.

Meanwhile, Perry's "Teenage Dream" album has produced a fifth number one hit, according to the L.A. Times.

"Last Friday Night (T.G.I.F.)" joins "E.T.," "Firework," "California Gurls" and the title track.

The "Teenage Dream" album has sold more than 1.5 million copies in the U.S.

When it comes to hair, Perry has tried on pretty much anything. Here's a look at the singer's ever-changing hair styles.