The old view of eye genetics was that blue was a recessive trait. In your case, dad has brown eyes because he has a dominant brown gene and a recessive blue gene. Similarly, mom has a dominant green gene and a recessive blue gene. You got the blue copy from each parent, hence blue eyes.
We now know eye color is determined by multiple genes and almost any parent/child color combination can occur. No need to check the mail man!
We now know eye color is determined by multiple genes and almost any parent/child color combination can occur. No need to check the mail man!