Examine source code of Page Filter Effects

{
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Set this page's color effect"
  },
  "description": "Fun filter effect for webpage.",
  "icons": {
    "16": "icon.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "manifest_version": 2,
  "name": "Page Filter Effects",
  "short_name": "PFE",
  "permissions": [
    "tabs",
    "http://*/*",
    "https://*/*"
  ],
  "version": "1.2"
}