We’re not sure what the brains behind St. Tropez-brand fake tanning lotions were thinking when they cast perpetually pale Kelly Osbourne as the line’s new poster girl — but she’s loving her new streak. “I’m not orange at all!” Kelly crowed last week from Los Angeles at her first shoot for the product. Osbourne started fake-baking during her stint on “Dancing With the Stars,” after the show’s powers-that-be complained that she was “the palest girl ever.” The newly bronzed beauty was still strutting her golden glow Friday night when she and identically pale fiancé Luke Worrall cmhere2turned up at LIV nightclub in Miami’s Fontainebleau. Spies said the couple canoodled, without Osbourne’s goop rubbing off on Worrall’s shirt, and “looked adorable.” A source confided, “They’re planning on getting married at the end of 2010.” Osbourne hasn’t said whether she plans to be a bronzed bride.