Template:Infobox/styles-images.css

@media screen {
  html.skin-theme-clientpref-night .infobox-has-images-with-white-backgrounds img {
      background: white;
  }
}

@media screen and (prefers-color-scheme: dark) {
  html.skin-theme-clientpref-os .infobox-has-images-with-white-backgrounds img {
      background: white;
  }
}