Subject: What is Hazel Eye Color and where does it fit in genetically?

I know that there is more to eye color than the standard Brown 
dominant/Blue recessive stuff we learn about in high school biology, but 
Hazel I am confused about.  My son's eyes are brown in the middle and blue 
towards the outside.  Is this hazel? And how does this happen? My husband 
and I both have brown eyes with one blue-eyed parent.  I've never seen 
such and eye color before and we were wondering what it was and how it 
came to be.

Re: What is Hazel Eye Color and where does it fit in genetically?