Lady Gaga

Where would a gallery about rainbow hair be without Gaga? Say what you want about her music and attention-seeking persona, but Gaga deserves credit for ushering in a new era of pop star costuming. In this photo taken during a visit to New Delhi, Gaga not only shows off a couple of unconventional colours (for once, not pink!), but she weaves them in a perfectly coiffed bun.