We can barely keep up with Katy Perry’s hair colour changes. We’re just getting used to the green, then this; a pink and black dip-dye. Spotted in a whimsy lyric video for her new single ...

Cosmopolitan.co.uk beauty icon of the week. American singer Katy Perry is our hair and makeup inspiration of the week. See how to get Katy's beauty look at the 2010 Grammy awards ...