A recent paper from Denmark (where else?) suggests that everyone with blue eyes is descended from a single ancestor. I have blue eyes and so find this particularly interesting. I think it is fair to say that blue eyes are considered more attractive than brown ones- though this isn’t a major factor when it comes to what we find attractive.
Usually you can find some evolutionary advantage to attractive features. But I cannot think of any advantage to having any particular eye colour. I think it is simply that blue eyes are in a minority and so have a bit of novelty value.