Hard to tell. This is the question you will only get guess answers for. I guess the main variation are dark and blue. The rest are some shades of either. The blue color is believed to be a recessive trait, meaning that it will only penetrate if 2 same genes were to be present, whereas the brown color is dominant, therefore requiring only one gene. The reality, though, often defies the above simple rule.
Depends. Eye color is surprisingly complex in terms of genetic inheritance. The color of a baby's eyes depends first on the color of their parents' eyes. Logically, baby's eyes should be similar in color to one or both parents. However, the complexities of eye color mean that, unless both parents have a really unique color pattern, baby can have lots of different eye colors.