<!DOCTYPE html>

  <meta charset="UTF-8">

  <title>CSS Reftest Reference</title>

  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">

  <style>
  div
    {
      background-color: yellow;
      color: green;
      display: inline;
      font-size: 300%;
    }
  </style>

  <script>
  function startReference()
  {
  document.getElementById("ref").focus();
  /*
  Some browsers, like Chromium 80+, will transfer focus
  to a selected element like a contenteditable div and
  therefore style the border of such element according
  to the user agent stylesheet rule:
  :focus {outline: -webkit-focus-ring-color auto 1px;} .
  So, we deliberately trigger such focus with the focus()
  method in the reference file.
  */
  document.getElementById("ref").style.caretColor = "yellow";
  /*
  When a contenteditable element is focused in Firefox
  82+, then the caret becomes visible and blinking and
  it is painted with the ::selected's color which is
  the green color in this case. We therefore counter,
  neutralize this by resetting the caret's color to the
  background color.
  */
  }
  </script>

  <body onload="startReference();">

  <p>Test passes if each glyph of "Selected Text" is green with a yellow background and if there is <strong>no red</strong>.

  <div contenteditable="true" id="ref">Selected Text</div>