Examine source code of Underworld Dark Theme

{
  "name": "Underworld",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "MQZnPxs.jpg"
    },
    "colors": {
      "frame": "rgba(1, 5, 15, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(0, 0, 0, 1)",
      "bookmark_text": "rgba(130, 120, 120, 1)",
      "toolbar_field": "rgba(130, 112, 112, 1)",
      "toolbar_field_text": "rgba(15, 3, 3, 1)"
    }
  }
}