Board Thread:General Discussion/@comment-26261153-20160118035903/@comment-25926288-20160213122248

The "black" you are seeing is purple,  darkish purple. So, likely there are three colors (purple, Blackish grey, and green), but still Austin's theory still stands.

The blackish grey could be what establishes Storybrooke as that was present in Regina's and Snow's curse, while it was absent in Pan's and Hook's curse.