Examine source code of Spoliarium

{
  "name": "Spoliarium",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "Spoliarium (3).jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(230, 230, 230, 1)",
      "toolbar": "rgba(20, 20, 20, 0.52)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(148, 148, 148, 1)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a8939eda-e981-4b67-a966-770acf75a6d0}"
    }
  }
}