The greenest celebs on the planet

Turns out green is a lot of celebrities' favorite color.

In honor of Earth Day on April 22, we've done a little digging to see who the most eco-friendly celebrities are, and what they're doing to help the planet. And while some of the bold-faced names, who choose to go green may surprise you, they definitely take the fate of the earth seriously.

From driving hybrid cars and living in solar-paneled houses to launching global initiatives and donating money, these stars have made the environment their priority.

Will Ferrell supports the Natural Resources Defense Council, and has built an eco-friendly home and drives around town in an electric car. Salma Hayek's on the board of Global Green USA, where she works to provide clean drinking water to people who need it around the globe -- and to fight global warming. Edward Norton helped to launch BP Solar, which provides solar electric systems for homeowners and businesses (including in some low-income housing). He also hosted a National Geographic TV special on environmental issues.

Meanwhile, in addition to being an avid vegetarian Natalie Portman released a line of vegan shoes in 2007, and went to Rwanda to film a documentary called "Gorillas on the Brink" the same year. And Leonardo DiCaprio deigns to fly commercial, drives a Prius, and launched the Leonardo DiCaprio Foundation to promote awareness of environmental issues like energy reform and carbon emissions. He also worked on and narrated "11th Hour," a 2007 documentary about the problems facing the Earth's life systems.

So apparently, it is easy "being green." To see a full list of the celebrities who are most globally conscious, check out the slideshow above.