Examine source code of Colors Changer

{
  "manifest_version": 2,
  "name": "Color Changer",
  "version": "1.0",
  "description": "Change the background color of the current webpage.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a5f75df8-6104-4c5b-905c-60700a143fde}"
    }
  }
}