It's pretty hard to separate Gwen Stefani from her signature look: platinum blonde hair and matte red lips. And since we've been pretty loyal fans ever since her "Tragic Kingdom" days, we've always been curious just where her beauty regimen came from.

As the cover girl for the September issue of Harper's Bazaar, Gwen dishes to the magazine about just where she got the idea to rock red lips. It turns out that her grandmother gave her her first red lipstick when she was still in high school:

I remember sitting in my ghetto, beat-up Honda Prelude, and putting on that lipstick in the rear-view mirror and being like, ‘Uh-huh, I like that. That’s the sh** right there.’ I never stopped after that.

Yup, we can definitely imagine the 42-year-old mom feeling pretty cool showing off her red lipstick as a subversive teen. These days, Gwen is pretty used to glamming it up though. The singer even confesses to putting on makeup multiple times a day and claims that she wears it at home for her husband Gavin Rossdale. “I like to make my husband like me more,” she says.

While she's certainly more high maintenance now, Gwen originally spent eight hours at the salon at the age of 25 to get her make her first foray into the world of platinum blonde hair. But, according to the "No Doubt" front woman, it was definitely worth it. “It was like I’d unlocked the key,” she says. “I remember feeling like, ‘I have arrived. This is me. Finally.’”

Check out Gwen's feminine cover and shoot and click over to Harper's Bazaar for more details about the September issue hitting newsstands August 21.

Scroll down for photos.

gwen stefani hair

gwen stefani hair

gwen stefani hair

See how Gwen Stefani's red lipstick and platinum hair has evolved over the years!

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  • July 1999

    Gwen Stefani performs as part of her band, No Doubt, at the Newport Beach Concert in Newport Beach, California.

  • December 1995

    Gwen Stefani backstage at the Berkely Community Theater.

  • June 1996

    Gwen Stefani backstage Live 105's BFD 1996 at Shoreline Amphitheatre in Mountain View, California.

  • January 1997

    Gwen Stefani at the 24th Annual American Music Awards.

  • December 1997

    Gwen Stefani at the 8th Annual Billboard Music Awards.

  • September 1998

    Gwen Stefani at the 1998 MTV Video Music Awards.

  • April 1999

    Gwen Stefani at the Hollywood premiere of "Go."

  • December 1999

    Gwen Stefani at the Christian Dior boutique opening in New York City.

  • February 2000

    Gwen Stefani at Vivienne Westwood's Fall 2000 fashion show.

  • December 2000

    Gwen Steani at the 2000 Billboard Music Awards.

  • June 2001

    Gwen Stefani at the 2001 MTV Movie Awards.

  • September 2001

    Gwen Stefani at the 2001 MTV Video Music Awards.

  • December 2001

    Gwen Stefani at the 2001 My VH-1 Music Awards.

  • December 2001

    Gwen Stefani at the 2001 Billboard Music Awards.

  • February 2002

    Gwen Stefani at the 44th Grammy Awards.

  • August 2002

    Gwen Stefani at the 2002 MTV Video Music Awards.

  • February 2003

    Gwen Stefani at the 45th Grammy Awards.

  • August 2003

    Gwen Stefani at T-Mobile Action Sports Team "Action-Packed" event in Hollywood, California.

  • November 2003

    Gwen Stefani at the 18th Annual American Cinematheque Awards honoring Nicole Kidman.

  • December 2003

    Gwen Stefani at the 2003 Billboard Music Awards.

  • February 2004

    Gwen Stefani at the 2004 Brit Awards.

  • August 2004

    Gwen Stefani at the 2004 MTV Video Music Awards.

  • November 2004

    Gwen Stefani performs on MTV TRL in New York City.

  • Nvember 2004

    Interscope Records CD release party for Gwen Stefani's "Love, Angel, Music, Baby."

  • December 2004

    Gwen Stefani at the 2004 Billboard Music Awards.

  • Febrauray 2005

    Gwen Stefani at the 2005 Brit Awards.

  • February 2005

    Gwen Stefani at the 47th Annual Grammy Awards.

  • February 2005

    Gwen Stefani at the premiere of "Constantine" in Hollywood, California.

  • March 2005

    Gwen Stefani at "The Girls" Fashion Week book launch party.

  • May 2005

    Gwen Stefani at MTV's "TRL" presents New Sounds of Summer at the Hard Rock Casino.

  • August 2005

    Gwen Stefani at the 2005 Teen Choice Awards.

  • October 2005

    Gwen Stefani 's celebration of the Harajuku Lovers Tour 2005 in Hollywood, California.

  • November 2005

    Gwen Stefani launches L.A.M.B. men's sneaker line at Barney's in New York City.

  • December 2005

    Gwen Stefani at the 2005 Billboard Music Awards.

  • February 2006

    Gwen Stefani at the 48th Annual Grammy Awards.

  • November 2006

    Gwen Stefani at the 2006 American Music Awards.

  • December 2006

    Gwen Stefani at the 2006 Billboard Music Awards.

  • January 2007

    Gwen Stefani at the 2007 NRJ Music Awards in Cannes, France.

  • October 2007

    Gwen Stefani attends the 4th Annual "Black Ball" Concert for "Keep A Child Alive" at Hammerstein Ballroom in New York City.

  • February 2008

    Gwen Stefani attends "A Night To Benefit Raising Malawi & UNICEF," hosted by Madonna and Gucci, at The United Nations in New York City.

  • February 2009

    Gwen Stefani at the 2009 Vanity Fair Oscar Party hosted by Graydon Carter.

  • September 2009

    Gwen Stefani attends Bloomingdale's celebration for Fashion's Night Out at Bloomingdale's 59th Street Store in New York City.

  • May 2009

    Gwen Stefani performs with her band, No Doubt, on NBC's "Today" show at Rockefeller Center in New York City.

  • October 2009

    Gwen Stefani attends Fashion Group International's 26th Annual Night of Stars at Cipriani Wall Street

  • November 2009

    Gwen Stefani arrives at MOCA 30th Anniversary Gala.

  • February 2010

    Gwen Stefani poses at the L.A.M.B Fall 2010 fashion presentation during Mercedes-Benz Fashion Week.

  • September 2010

    Gwen Stefani at Mercedes-Benz Fashion Week Spring 2011.

  • November 2010

    Gwen Stefani arrives at "The Artist's Museum Happening" MOCA Los Angeles Gala.

  • December 2010

    Gwen Stefani poses for a photo at the 33rd Annual Kennedy Center Honors in Washington, D.C.

  • February 2011

    Gwen Stefani backstage at the L.A.M.B. Fall 2011 fashion show.

  • May 2011

    Gwen Stefani in London, England.

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