Examine source code of Color Picker

{
  "manifest_version": 2,
  "name": "Color Picker",
  "version": "1.0",
  "description": "Pick and display color codes from any part of the page.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{25f2c911-49a7-4e6c-aa20-730be9abfc21}"
    }
  }
}