JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
  <li>
    <a>link 1</a>
      <img src="http://lorempixel.com/100/100" />
  </li>
  <li>
    <a>link 2</a>
    <img src="http://lorempixel.com/100/100" />
  </li>
  <li>
    <a>link 3</a>
    <img src="http://lorempixel.com/100/100" class="whiteImg" />
  </li>
</ul>

CSS

body {
    background: #F5F5F5;
    color: #333333;
    -webkit-transition: 2s;
    transition: 2s;
}
body.dark {
    background: #333333;
    color: #F5F5F5;
}

JavaScript

$("li:has(.whiteImg)").hover( function() {
    $("body").addClass("dark");
}, function() {
    $("body").removeClass("dark");
});