Examine source code of Color Inverter

{
  "manifest_version": 2,
  "name": "Color Inverter",
  "version": "1.3.2",
  "description": "Inverts all the colors on a page. Toggle a domain by visiting it and then clicking on the extension's icon in the menubar.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "icons": {
    "48": "icons/icon_48.png",
    "64": "icons/icon_64.png",
    "96": "icons/icon_96.png",
    "128": "icons/icon_128.png"
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon_48.png",
      "64": "icons/icon_64.png",
      "96": "icons/icon_96.png",
      "128": "icons/icon_128.png"
    },
    "default_title": "Toggle inversion of colors for this domain."
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "ColorInverter@Hugh.Calan.com"
    }
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+Shift+I"
      },
      "description": "Toggle color inversion"
    }
  }
}