From Wikipedia:
There is some difficulty in defining the eye color "hazel" as it is sometimes considered to be synonymous with light-brown and other times with dark green.[32][20][25][27][30][33] They have been described as dark green or yellowish brown,[34] or as a lighter shade of brown.[35] Hazel eyes have also been described as being equivalent to a dark green or amber color eyes/light brown.[36] In North America, "hazel" is often used to describe eyes that appear to change color, ranging from light brown to green and even gray, depending on current lighting in the environment.
Hazel eyes are not in the blue family as many people mistakingly believe. My husband has hazel, mine are green and our son has blue. Hubby and I each had one parent with brown eyes and one with blue.