Guess what color Gwen Stefani is promoting in her new commercial for L'Oréal Paris?

Red, of course!

Donning signature bright-crimson lips, the songstress turned designer turned model is a hit in the latest L'Oréal Paris ad promoting its Infallible La Rouge Lip Color.

The mass-market beauty brand just announced Stefani last week and wasted no time getting the "Hollaback Girl" on air to advertise its long-lasting, soft-shine lip color infused with Vitamin E.

The 41-year-old lipstick-loving songstress now joins the ranks of other Hollywood pop stars like Beyoncé and Jennifer Lopez in representing L'Oréal Paris -- and looking just as fabulous on-screen as they do onstage.

So far, Gwen and her bright-red pout are a definite favorite though!

Interestingly enough, Stefani says it's her rocker husband, Gavin Rossdale, who encourages the bold look.

"I don't always wear red lipstick -- people think they see me every day, but they don't!" she told StyleList in an earlier interview. "I change it up. But my husband really loves the red, so I keep the red because I want to keep the husband," she laughed.

Could there be a better choice to promote L'Oréal's lip color? When you see Stefani working the camera so well, we think not. Her mouth just takes center stage as she bounces around the screen in gorgeous white, red and black outfits.

It's enough to make us want to slather our lips in Ravishing Red. How about you?

Read more about Stefani and her latest fragrance line.