Examine source code of Background colour Changer

{
  "manifest_version": 2,
  "name": "Background Changer",
  "version": "1.0",
  "description": "Changes the background color of a webpage.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0b0c6e82-b7c6-4d3b-9411-2799d93dc126}"
    }
  }
}