An uneven skin tone is caused by an uneven distribution of pigment. Sun exposure and hormonal changes can also contribute to this issue. Certain serums, creams or moisturizers, especially those that contain vitamin C, can all help to even out your skin tone. It is also possible that your skin can develop an uneven tone due to a buildup of dead skin cells. If that is the issue, a simple way to even out your skin tone is to exfoliate once to twice weekly.