It was only last week I was blogging about Katy Perry's new hair and before i'd even starting adjusting to the blonde a new colour emerges: Pink! Katy isn't the only celebrity to be influenced by the colours of the rainbow when craving a hair change, Kate Bosworth was also seen this with with a blue dip dye. Prior to this Lauren Conrad also tweeted a picture of her rainbow hair. The proof is all below in the pictures but what do you think? Is brightly coloured hair the new trend?