Gwen Stefani wore black and white stripes with leggings yesterday as she headed into an LA studio to continue working with No Doubt on their upcoming album. She tweeted photos of her bandmates' wives between songs, but her husband, Gavin Rossdale, wasn't able to hang out — she sent a sweet "hi muffin" to him instead. Gwen had a break from music to visit a park with her sons Zuma and Kingston Monday on Martin Luther King Jr. Day, but she's back to business now during the workweek. Her other new project, a commercial with L'Oréal, just debuted, and it features Gwen looking gorgeous in her signature red lip color. The company also just released another video, showing a behind-the-scenes look at a shoot at the Hollywood sign.