Brown(Robert) + Green(KaDee) = Everything

I still don't understand the genetics that go in to deciding eye color. I've read about and been told about it but I still see no rhyme or reason that eyes turn out the colors they do. I thought for sure we'd have all brown eyed kids. Our kids each have a different shade of eyes.
                                                                      Dark Blue

(sometimes I think they're grey)

Dark Brown

                                                                          Hazel

                                                                         Light Blue