theme.park/css/community-theme-options/trueblack.css

:root {
  --main-bg-color: #000;
  --modal-bg-color: #000;
  --modal-header-color: #000;
  --modal-footer-color: #000;

  --drop-down-menu-bg: #000;

  --button-color: #7a7a7a;
  --button-color-hover: #9b9b9b;
  --button-text: #ddd;
  --button-text-hover: #999;

  --accent-color: 170, 170, 170;
  --accent-color-hover: rgba(153, 153, 153, 0.45);
  --link-color: #7a7a7a;
  --link-color-hover: #999;
  --label-text-color: black;

  --text:#ddd;
  --text-hover: #999;
  --text-muted: #5a5a5a;

  /*Specials*/
  --arr-queue-color: #ddd; /* Servarr apps + Bazarr*/
  --plex-poster-unwatched: #ddd;
  --petio-spinner: invert(35%) sepia(0%) saturate(6%) hue-rotate(136deg) brightness(95%) contrast(87%);/* Made with https://codepen.io/jsm91/embed/ZEEawyZ */
  --gitea-color-primary-dark-4: 170, 170, 170;
  --overseerr-gradient: linear-gradient(180deg, rgba(0, 0, 0, 0.17) 0%, rgba(0, 0, 0) 100%);
}