My first recommendation would be just to get a wig. It would be easier to chose the character based on the clothing you have, and then to get the wig to match. Less expensive, too.
However, if wigs are out, here are a couple of characters I can think of with teal hair: Klarinette from .hack, Amiti from Golden Sun, Alex from Golden Sun, Nel from Bleach, and Sailor Neptune. Oh, and there's always Noah Kaiba.