JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
  <li>one</li>
  <li>two</li>
  <li>three</li>
</ul>

CSS

ul {
  display: inline-block;
  list-style: none;
  margin: 0; padding: 0;
}
ul:hover li:not(:hover) {
  color: #000;
}
ul li:first-child,
ul li:hover {
  color: blue;
}