Eye color develops from iris pigmentation and the scattering of light. If your adult eye color changes pretty dramatically, or if one eye changes from brown to .
But if you notice an actual color change in one or both eyes, see a doctor for a A cataract - cloudy lens behind the pupil - seen in an adult eye.
If you've ever thought your eyes have changed color - you're not going crazy. There are a lot of reasons why your eyes might at least appear to.