Examine source code of ColorPicker Pro

{
  "manifest_version": 2,
  "name": "ColorPicker Pro",
  "version": "1.0",
  "description": "ColorPicker Pro is an innovative Firefox add-on that empowers designers to extract and manage color palettes directly from any webpage.",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{31455342-0f32-4272-8ac0-1f4523ea4d66}"
    }
  }
}