Lately I've noticed my once pearly-white teeth have developed an off yellowish tinge, which is no doubt a worry for me! I do drink alot of green tea and coffee, but no more than a combined total of 2 or 3 a day, and I am into my sugar unfortunately. I brush and floss twice a day. Is it too late to get my teeth back to the white shade they were before naturally?? I really dont want to pay for teeth whitening, and would be willing (though devastated!) to give up green tea and coffee if thats what it came too. If it is something I can reverse, what sort of foods should I eat to improve the appearance?