Examine source code of Falling Dice

{
  "theme": {
    "images": {
      "theme_frame": "FirefoxHeader.jpg"
    },
    "colors": {
      "frame": "#6e6e6e",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Falling Dice",
  "manifest_version": 2,
  "description": "Falling Dice in white"
}