Ricky Martin, Julianne Moore, 'DWTS' Carson Kressley and 'Jersey Shore' Cast Among Participants on Spirit Day

To show support for gay youth and to stand up against bullying, celebrities like Grammy-winning artist Ricky Martin and Oscar-nominated actress Julianne Moore, and media companies, like NBCUniversal, are taking part in Spirit Day on Thursday.

MTV will change their on-air logo purple, the second time in the cable network's history where they will be changing the logo for a cause. NBCUniversal and Viacom are also encouraging employees and talent to participate.

Sundance Channel, USA Network's "Characters Unite" and Logo are also changing their on-air and social media logos that day. Additionally, teen fashion magazine, Seventeen, will also do the same.

In addition to Martin and Moore, celebrities who will wear purple in support include Allison Janney, Sara Ramirez, Chaz Bono, Mia Farrow, Vinny Guadagnino and Sammi Giancola of Jersey Shore, Teen Mom cast members, Jaime Pressley, talent from World Wrestling Entertainment, the Awkward cast, Carson Kressley, Bravo's Andy Cohen and Real Housewives' Sonja Morgan, 90210's Shenae Grimes, The Biggest Loser's Bob Harper and the cast from Degrassi.

Hosts like Conan O'Brien, Wendy Williams and the women of The View will also wear purple on the air. Additionally, the lights at the Los Angeles International Airport will be lit purple on Thursday.