SAN FRANCISCO – Apple Inc.'s eye-catching logo - an apple with a bite taken from it - has come in many colors in the past. Now, the iconic computer company is trying to prove its commitment to the color green.

In recent advertising, the Cupertino, Calif., company presents itself as an environmental leader. Apple's Web site bills its new line of MacBook computers as "the world's greenest family of notebooks." It now makes iPods and iPhones free of polyvinyl chlorides and brominated flame retardant, and it's in the final...