Examine source code of Grid_Three

{
  "theme": {
    "images": {
      "theme_frame": "Grid_Three_Head.png"
    },
    "colors": {
      "frame": "#757474",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Grid_Three",
  "manifest_version": 2,
  "description": "This is Grid Three"
}