Examine source code of Tropea Dark Grey

{
  "name": "Tropea Dark Grey",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "Progetto senza titolo(6).png"
    },
    "colors": {
      "frame": "rgba(51, 58, 65, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(84, 84, 84, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(51, 58, 65, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4c887b58-dcf7-4d34-91a0-fa5a4e661248}"
    }
  }
}