Katie Holmes attends amfAR Inspiration Gala in Sao Paulo, April 27, 2017.

Kristen Stewart attends the "Personal Shopper" Premiere, Carondelet House in Los Angeles, March 7, 2017.

Allison Williams posted this photo to her Instagram account, Feb. 8, 2017.

Ruby Rose posted this photo her Instagram account, Dec. 16, 2016.

Uma Thurman attends the Pirelli calendar 2017 by Peter Lindberg launch press conference at Hotel Salomon de Rothschild on Nov. 29, 2016, in Paris.

America Ferrera arrives at the NBC and Vanity Fair Toast to the 2016-2017 TV season, Nov. 2, 2016, in Los Angeles.

Kristen Stewart attends the "Certain Women" premiere during the 54th New York Film Festival, at Alice Tully Hall at Lincoln Center, Oct. 3, 2016, in New York City.

Bethenny Frankel is seen at an exclusive viewing of "Real Housewives of New York City" to launch the latest Skinnygirl Cocktails, Aug. 17, 2016, in New York.

"Game Of Thrones" actress Sophie Turner shared this image to her Instagram account for her newly dyed platinum hair, Aug. 4, 2016.

Tori Spelling sports new pink hair as she celebrates Fourth of July weekend with her family in Malibu, Calif., July 3, 2016.

Sarah Hyland posted this photo of her new hairstyle to her Instagram account with the caption, "Finally saying goodbye to my Lisa Houseman hair and bringing in the rest of the summer vibes," June 17, 2016.

Emma Stone is pictured with blond hair in New York, June 2, 2016.

Jenny McCarthy visits SiriusXM Studios on May 11, 2016 in New York City.

Kylie Jenner is pictured at an event with Sama Khadra and Haya Khadra in Palm Springs, Calif., April 15, 2016.

Taylor Swift shared this image to her Instagram, debuting a new hair do, April 15, 2016.

A blue haired Kesha was spotted at LAX in Los Angeles, March 19, 2016.

Khloe Kardashian was spotted showing off her platinum curls, with one side of her head shaved, while out for lunch in Beverly Hills, March 17, 2016.

Gwen Stefani seen at LAX airport in Los Angeles, March 16, 2016.

Joe Jonas is seen leaving the BBC Radio 1 Studios, March 9, 2016, in London, England.

Sarah Michelle Gellar is seen in a photo posted to her Instagram account, March, 5, 2016.

Zendaya is seen at 'Jimmy Kimmel Live' on Feb. 10, 2016 in Los Angeles.

Emma Stone is spotted leaving a salon with a dark new hair look for the role of her new upcoming movie, Feb.5, 2016, in Los Angeles.

A photo of Allison Williams with bangs was posted to her Instagram account, Jan. 28, 2016.

Bethenny Frankel arrives at the Skinny Girl Candy Launch at Dylan's Candy Bar on Jan. 26, 2016 in New York City.

Alyssa Milano showed off a new pixie cut hairstyle in an image she shared on her Instagram, Dec. 19, 2015.

Hilary Duff posted this selfie to Instagram on Dec. 19, 2015 with the caption, "Soooo it's pretty short. Thank you @cynthiavanis chopping."

Jennifer Aniston is seen in character wardrobe on the set of 'The Yellow Birds' in Atlanta, Dec. 12, 2015.

Lauren Cohan attends Z100's Jingle Ball 2015 at Madison Square Garden, Dec. 11, 2015 in New York City.

Actress Ali Larter is spotted with auburn hair at a grocery store in Los Angeles, Dec. 4, 2015.

Alyson Hannigan is seen in Los Angeles, Dec. 9, 2015.

Kylie Jenner is seen in West Hollywood, Calif., Nov. 30, 2015.

Gigi Hadid arrives at the 2015 American Music Awards at Microsoft Theater, Nov. 22, 2015, in Los Angeles.

Jared Leto arrives to Museum of Modern Art on Nov. 4, 2015 in New York.

Jared Leto seen in SoHo on Oct. 8, 2015 in New York City.

Ryan Reynolds arrives at the "Mississippi Grind" premiere during the 2015 Toronto International Film Festival held at Roy Thomson Hall on Sept. 16, 2015 in Toronto.

Elisabeth Moss attends the premiere of "High-Rise" during the 2015 Toronto International Film Festival at the Elgin, Sept. 13, 2015 in Toronto.

Molly Sims appears in a photo posted to her Instagram account on Sept. 9, 2015 with the text, "LOVE IT #done."

Sienna Miller attends Nine By Savannah Miller for Debenhams launch party at the Ham Yard Hotel, Sept. 8, 2015, in London.

Dakota Johnson attends day 3 of the 72nd Venice Film Festival, Sept. 4, 2015, in Venice.

Justin Bieber arrives at the 2015 MTV Video Music Awards at the Microsoft Theater on Aug. 30, 2015, in Los Angeles.

Miranda Lambert posted this photo to Instagram on Aug. 20, 2015 with the caption, "What doesn't kill you only makes you blonder."

Singer Britney Spears poses in the press room at the Teen Choice Awards 2015 at Galen Center in Los Angeles, Calif., Aug. 16, 2015.

Model Gigi Hadid poses at David Jones Elizabeth Street, Aug. 7, 2015, in Sydney.

Rumer Willis was seen in Hollywood on July 30, 2015.

Giuliana Rancic shared this photo on Instagram on July 29, 2015.

Jenny McCarthy was seen in New York, July 14, 2015.

Kylie Jenner arrives on the red carpet with mint green hair at Bellami Beauty Bar, July 9, 2015, in West Hollywood, Calif.

Nicole Richie attends VH1's "Candidly Nicole" Season 2 Premiere Event at House of Harlow at The Grove, July 7, 2015, in Los Angeles, Calif.

Ke$ha is seen as she arrives at LAX airport in Los Angeles on June 18, 2015.

Actress Jada Pinkett Smith visits the SiriusXM Studios, June 3, 2015, in New York.

Jennifer Lopez gets "Glitter-Bombed" by a clown as she catches a flight out of Los Angeles, May 27, 2015.

Kesha posted this photo to Instagram on May 23, 2015.

Bethenny Frankel debuts her new look at a Skinnygirl Cocktails viewing party with fans, Tuesday, May 19, 2015 in New York.

Madonna posted this photo to Instagram, May 15, 2015.

This image was posted to Kaley Cuoco's Instagram account on April 29, 2015.

Jared Leto shows off his green Joker hair as he rides his bike around Toronto, April 26, 2015. Jared, who wore a puffy jacket, shorts, and tights, is in town filming 'Suicide Squad.'

Tyra Banks arrives at the 42nd Annual Daytime Emmy Awards held at Warner Bros. Studios, April 26, 2015, in Burbank, Calif.

Actress Hilary Duff smiles while arriving to a studio in Los Angeles on April 23, 2015.

This image was posted to Hilary Duff's Instagram account on April 20, 2015.

Khloe Kardashian is seen at LAX on April 07, 2015 in Los Angeles.

Julianne Hough posted this photo to Instagram on April 7, 2015 with the caption, "Pink hair don't care! Check out my new fun hair and get @riawnacapri's fabulous tips on becoming a "unicorn."

Katy Perry posted this photo on Instagram with this caption: "I asked for the Kris Jenner," April 1, 2015.

Baby Buggy Founder Jessica Seinfeld attends the Inaugural Los Angeles Fatherhood Lunch to Benefit Baby Buggy hosted by Jerry Seinfeld at The Palm Restaurant, March 4, 2015, in Beverly Hills, Calif.

David Ayer posted this photo to Twitter on March 2, 2015.

Giuliana Rancic is seen in this photo posted to Instagram on Feb. 19,2 015 with the caption, "Closer look at my new hair color!"

Actress Kerry Washington arrives at The Daily Front Row's 1st Annual Fashion Los Angeles Awards at Sunset Tower Hotel, Jan. 22, 2015, in West Hollywood, Calif.

Nicole "Snooki" LaValle posted this photo to Instagram on Jan. 14, 2015 with the caption, "LOVING this. So much easier to maintain and my kids won't have anything to hang off of anymore".

Kate Bosworth is pictured on Jan. 13, 2015 in New York City.

Chris Hemsworth arrives at JFK Airport in New York, Jan. 11, 2015.