JSFiddle - React, Tailwind, and code Playground

HTML

<html>

  <body style="background-color:#299">
    <ol>
      <li class='hex'>
      </li>
    </ol>
  </body>

</html>

CSS

.hex {
  width: 10px;
  height: 10px;
  text-indent: -999px;
  background-color: #000\9;
  background-color: rgba(0, 0, 0, 0);
  border: 1px solid #fff;
}