The main character, the playable character, Link-- it's kinda his colour. He grew up in the Kokiri forest, never knowing he wasn't one of them, and was actually another race from someplace else. Not until he started to grow, 'cause see, the Kokiri stay small their whole lives so then he knew. But even then, when he was cast out, he kept wearing green. The colour of the forest. 'Cause even though his destiny was elsewhere, that was still his home.