Examine source code of MyTransparentTheme

{
  "name": "MyTransparentTheme",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "python.svg"
    },
    "colors": {
      "frame": "rgba(48, 48, 48, 0.06)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(46, 46, 46, 0.83)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(38, 38, 38, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a656f11a-2ee0-4375-8464-ec31a491e9e7}"
    }
  }
}