changed the JSON format for iOS

I've changed the JSON to be formatted as an array of “palettes” as follows:
````json
[
  {
    "palette" : "primitive"
    "comment" : "the comment string"
    "swatches" : [
       {
          "swatch" : "red"
          "values" : [
             0.000,
             0.000,
             0.000,
             1
          ]
       }
    ]
  }
]
````