Examine source code of IT background

{
  "name": "IT background",
  "description": "Now you can Change the current page color",
  "version": "1.1.7",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_title": "IT background",
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "manifest_version": 2
}