Our jaws hit the floor when we saw Gwen Stefani's new look at the Billboard Music Awards this past weekend. The pop icon, who has become known for her pinup hair and red lips, showed up sporting a much more subdued style: monochromatic makeup and down-to-there curls. Our thoughts? We totally dug this new incarnation of Gwen.However, if you think this is the first time the singer/designer/host/all-around boss has switched up her look, you're in need of a history lesson. Since winning our hearts as the lead crooner of No Doubt, Gwen has gone through many beauty transformations — and they've all been noteworthy.Click through to take a stroll down memory lane. The only thing left to wonder? What Gwen will try next.