Examine source code of FUNcraft

{
  "theme": {
    "images": {
      "theme_frame": "_0_2500.jpg"
    },
    "colors": {
      "frame": "#810000",
      "tab_background_text": "#000065"
    }
  },
  "version": "2.0",
  "name": "FUNcraft",
  "manifest_version": 2,
  "description": "Fog theme"
}