Examine source code of Adwaita Custom (suckless)

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Adwaita Custom (suckless)",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(40, 40, 40)",
      "toolbar_text": "rgb(240, 240, 240)",
      "frame": "rgb(47, 47, 47)",
      "tab_background_text": "rgb(218, 218, 218)",
      "toolbar_field": "rgb(47, 47, 47)",
      "toolbar_field_text": "rgb(240, 240, 240)",
      "tab_line": "rgb(0, 85, 119)",
      "popup": "rgb(40, 40, 40)",
      "popup_text": "rgb(218, 218, 218)",
      "tab_loading": "rgb(0, 85, 119)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1f3394e1-4bcd-4f5b-953e-feca4bc2d62e}"
    }
  }
}