Examine source code of Alone by M♥Donna

{
  "name": "The End by M♥Donna",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "The End T.jpg"
    },
    "colors": {
      "frame": "rgba(59, 35, 33, 1)",
      "tab_background_text": "rgba(253, 255, 224, 1)",
      "toolbar": "rgba(61, 37, 34, 0)",
      "bookmark_text": "rgba(253, 255, 224, 1)",
      "toolbar_field": "rgba(61, 37, 34, 0.06)",
      "toolbar_field_text": "rgba(253, 255, 224, 1)",
      "tab_line": "rgba(253, 255, 224, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e5ee028-a160-40c7-8c9c-de4f85a983f3}"
    }
  }
}