If this question has ever tormented you (in other words, if you have too much time on your hand or, conversely, if like me, you have too much to do at the moment and are therefore artfully procrastinating)... check out:
http://museum.thetech.org/ugenetics/eyeCalc/eyecalculator.html It tells you what color eyes your kids would have between any two potential partners, taking into account grandparents' eye color. And explains why.