I think red or violet. When we take photoes at night or in poor light, we inevitably appear red eyes, which seems really horrible. That shall be one of the reason why the photoshop is so popular worldwide. In general, eye's iris pigmentation and light scattering frequency determine the eye color. Various eye colors can occur in different parent-child combinations due to the complex eye color genetics. Technical saying, it is impossible for human beings to have blue or purple eyes. As a rule, we can see blue-eyed siamese cats and jungle crows. In fact, those colors may be a sign to indicate the pathological changes when they exist in human body, like albinism etc. Some Americans have blue eyes just because of the light scattering making it look like blue, especially for lighter-colored eyes. By the way, I favor amber eyes. Have a good day.