I don't know about colour combos, but the advice I always give when you don't know what you're doing in regards to colour is to leave it to the pros. Take your photo in, get a colour consultation from a specialist. You can always ask what you can do to maintain/touch it up on your own. (If you can't afford a colour job at a salon, try a beauty school. It's often cheaper, and you'd be helping students get hands-on experience.)