From my shark website:
Sharks have several eye configurations; such as a contrasting Iris, with vertical slit pupils, horizontal slit pupils, or more rounded pupils, similar to our eyes. The eyes are also of different colors. Some shark species have black eyes, but many other sharks do not. When I say black, that is what it will look like to you and me at a distance. Inside of the outer coating on some shark's eyes there may be a diferent color in there, that can only be seen from a very short distance. Sandtigers have yellow eyes with a round black pupil.