Katy Perry rocks dark purple and blue hair. Photo: Tom Wargacki, WireImage

Never one to shy away from outrageous hairstyles, Katy Perry actually appeared more subdued this week -- even with blue hair.

As part of the promotional tour for her new album, "Teenage Dream," Perry greeted fans in London with dark purple and blue hair extensions -- the colors of fiancé Russell Brand's soccer team, West Ham United.

The 25-year-old popstar -- who caused quite a stir during her last visit to the U.K. with an oh-so-tight polka dot dress -- signed autographs outside the London Studios yesterday looking happy and carefree.

You may recall Perry's rainbow locks -- albeit wigs -- that she donned last month in a fashion spread for the Guardian's magazine. The outspoken star switched it up from strawberry red to peacock blue to electric green. And as bold as they were, she managed to pull them off like only Katy Perry could.

Fans who adore her avant-garde style will be glad to know that Perry doesn't expect to tame her looks just because she's settling down with a new hubby.

Meanwhile, if you thought some of her wigs were outrageous, nothing can compare to this look!