The color hazel is defined as a light golden brown, similar to that of a hazelnut. Hazel is most commonly used to refer to a person's eye color.
Many people with hazel eyes find that their eye color changes from a light brown to a greenish- yellow color, depending on their surroundings. Hazel eyes generally have a high concentration of pigment around the border of the eye. Interestingly, no one knows for sure how hazel eyes occur in terms of genetics. It is clear that hazel eyes contain more melanin, or pigment, than green or blue eyes and less melanin than brown eyes.