Цвет глаз - сложная штука, комбинации у детей и родителей могут быть разными. Пара цитат:

The genetics of eye color are so complex that almost any parent-child combination of eye colors can occur.
http://www.medterms.com/script/main/...ticlekey=25003

“So contrary to what used to be thought, it is possible for two blue-eyed parents to have a brown-eyed child, although this is not common.”
http://www.sciencedaily.com/releases...0222180729.htm