Katy Perry Roberto Cavalli Katy Perry PRISM Tour Roberto Cavalli may not love all American women, but he sure does like some of the most famous ones -- enough to design tour costumes for them. First came Beyonce in a controversial gown and Miley Cyrus in next to nothing. Now, Katy Perry is getting the Cavalli treatment, too. The singer/songwriter will wear Cavalli on her highly anticipated Prism tour. Compared to Bey, whose gown was just as sexy as it was elegant and Miley, who despite what you think of her style is one of the only people who could actually pull these looks off, Perry's outfits are very ... her. From the color to the design, they ooze the singer's aesthetic.