Examine source code of Favorite Background Color

{
  "manifest_version": 2,
  "name": "Favorite Background Color",
  "version": "1.0",
  "description": "Change the webpage's background color to your favorite color.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/color-change-48.png",
    "default_popup": "popup.html",
    "default_title": "Change Background Color"
  },
  "icons": {
    "48": "icons/color-change-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ec29995d-4253-46ac-8c3e-5714d07164b6}"
    }
  }
}