Examine source code of Steam Deck UI

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Steam Deck UI",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(14, 20, 27)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(35, 38, 46)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(35, 39, 48)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(26, 159, 255)",
      "popup": "rgb(35, 38, 46)",
      "popup_text": "rgb(255, 255, 255)",
      "ntp_background": "rgb(14, 20, 27)",
      "popup_highlight": "rgb(26, 159, 255)",
      "tab_selected": "rgb(14, 20, 27)",
      "tab_loading": "rgb(26, 159, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6b3c3bbf-e459-4bff-a01b-7d5e6370e717}"
    }
  }
}