Sadly, this is probably the best recipe AllRecipes has to offer. It is close to the traditional recipe in most ways (uncooked filling, standard crust), but to be a Key Lime Pie it has to be made with Key Lime juice. Key limes are much different than the standard Persian limes, with an entirely different flavor. No lemon juice, standard is about 1/2 cup Key Lime juice (about 3/4 lb. fruit). Under no circumstances should green food coloring be used; the filling should be yellow. Whipped cream is pretty common now, but meringue was used first- the pie was developed at a time when there was practically no refrigeration in the area (south Florida).