The natural colour of teeth is within a range of light greyish-yellow shades. The degrees of brightness depend on many factors such as age, genetics, trauma or disease, dental hygiene, medication uses, and foods and drinks consumed. Some of these factors can possibly be prevented, but some cannot. Avoiding the following foods and drinks may help prevent further discolouration of your teeth: coffee, tea, dark sodas, colas, wines, tobacco, and some dark and vibrant vegetables and fruits.