Well, actually people have different eye colors. So you should know the reasons about it. Generally speaking, the pupil which is the black spot in the middle of your eye will allow light to enter the eye. It is a hole. And around this hole is the colored part of the eye, which is named as the iris. For iris which has pigment, it regulates the size of the pupil and how much light is allowed into the eye. So we can say that the iris give the eye its color because of the pigment. If there are large amount of pigment present, the color of the eye would be black, brown or hazel. Of course, small amounts would result in light green or light blue eyes. that why people have different colors.