Examine source code of Acnh

{
  "name": "Acnh",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "acnh-4.png"
    },
    "colors": {
      "frame": "rgba(173, 0, 0, 1)",
      "tab_background_text": "rgba(214, 214, 214, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ce170ca7-e997-4613-adbc-dee634bb4eeb}"
    }
  }
}