[spirit_queen]

I say an olive green. If you want to follwo through with blue, realy dark blue. A grey might be okay. Since you don't want to look unnatural, I'm not suggesing unnatural colors. But I still say olive green.

It would really help for you to post a picture of yourself, or find a picture of someone with the same iris shade as you, so we could try to determine a more precise shade for your eyes.