Examine source code of Retro Color Picker

{
  "manifest_version": 2,
  "name": "Retro Color Picker",
  "version": "1.0",
  "description": "Pick colors from any webpage and memorize the last 5 picked colors.",
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Retro Color Picker",
    "default_icon": {
      "48": "icons/icon-48.png"
    }
  },
  "icons": {
    "48": "icons/icon-48.png"
  },
  "commands": {
    "start-picking": {
      "suggested_key": {
        "default": "Alt+Shift+C"
      },
      "description": "Start Retro Color Picker"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "retrocolorpicker@ghasali.id",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}