chromium/ui/webui/resources/css/md_colors.css

/* Copyright 2016 The Chromium Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file. */

html {
  /* This is a custom, Chrome-specific color that does not have a --paper or
   * --google equivalent. */
  --md-background-color: rgb(248, 249, 250);
  --md-loading-message-color: #6e6e6e;
  --md-toolbar-height: 56px;
  --md-toolbar-border: 1px solid #e0e0e0;
}

@media (prefers-color-scheme: dark) {
  html {
    --md-background-color: rgb(32, 33, 36);  /* --google-grey-900 */
    --md-loading-message-color: #9AA0A6;  /* --google-grey-500 */
    /* --cr-separator-line */
    --md-toolbar-border: 1px solid rgba(255, 255, 255, .1);
  }
}