Examine source code of Colorless for Firefox

{
  "manifest_version": 2,
  "name": "Colorless for Firefox",
  "version": "1.0.1.1resigned1",
  "author": "Hereafter",
  "home_url": "https://github.com/hereafter/colorless",
  "applications": {
    "gecko": {
      "id": "ColorlessFirefox@hereafter.github.com"
    }
  },
  "browser_action": {
    "default_icon": "images/icons/icon_32.png",
    "default_title": "Colorless for Firefox",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/decolorize.js"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "scripts": [
      "js/app.js",
      "js/background.js"
    ],
    "persistent": true
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "default_locale": "en",
  "description": "Remove colors for visiting pages",
  "permissions": [
    "*://*/*",
    "tabs",
    "contextMenus"
  ],
  "icons": {
    "16": "images/icons/icon_16.png",
    "48": "images/icons/icon_48.png",
    "128": "images/icons/icon_128.png"
  }
}