Well, generally speaking, stress can not change the color of your eyes. According to some researches, stress is not a factor which can change the color of the eyes completely. But on the other hand, stress can affect how dark or light the eyes become in color. You should know that when you suffer stress, the density and distribution of the melanin on the eyes will change. In this way, it will make the eyes look darker or lighter. By the way, you should know that the color of your eyes can change with the emotion. When you are sad and cry, it can turn to light grey and light blue. Even some drug which will have side effect that it can change the color of your eyes. so just be careful about it.