I have green eyes too and I find that amethyst and peridot are the most flattering. Yes, purples and greens, imo. That, and a beautiful shimmery eye shadow. Oh, and yellow gold, even though I like white metals better in general. I know this is a little off topic, but golden highlights near the face makes green eyes really pop!
I was also thinking about going with some gold earrings with amethyst. I'm a blue topaz kind of girl, but I'd really like to get some earrings that will make my eye color seem maybe a bit more intense than it is.