Cavalli Works with Katy Perry–Pop star singer Katy Perry is teaming up with quite a few designers for her Prismatic World Tour which starts on May 7th. Among them, the “Dark Horse” singer has collaborated with Roberto Cavalli (who also designed for Miley Cyrus’ Bangerz tour) for two looks and the result is a playful juxtaposition of pastel colors and metallic accents. A fringe embellished dress and pleated skirt with a matching crop top look are included in the lineup. See more below.