Examine source code of Libadwaita Dark

{
  "manifest_version": 2,
  "version": "1.3",
  "name": "Libadwaita Gnome Dark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(34, 34, 38)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(46, 46, 50)",
      "tab_background_text": "rgb(188, 194, 199)",
      "toolbar_field": "rgb(29, 29, 32)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(53, 132, 228)",
      "popup": "rgb(56, 56, 60)",
      "popup_text": "rgb(244, 244, 244)",
      "ntp_background": "rgb(34, 34, 38)",
      "sidebar_text": "rgb(244, 244, 244)",
      "sidebar": "rgb(56, 56, 60)",
      "toolbar_field_border_focus": "rgb(53, 132, 228)",
      "tab_loading": "rgb(53, 132, 228)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0e5278ed-c56c-490c-b6ef-e521dbc06a7b}"
    }
  }
}