Examine source code of firefox play ball

{
  "theme": {
    "images": {
      "theme_frame": "cartoon_fox.PNG"
    },
    "colors": {
      "frame": "#b56a1f",
      "tab_background_text": "#b56a1f"
    }
  },
  "version": "2.0",
  "name": "firefox play ball",
  "manifest_version": 2,
  "description": "firefox ball trapped by cheeky fox x"
}