W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
  <title>Change Color</title>
  <style>
    #app {
      border: dashed black 1px;
      width: 350px;
      padding: 0 20px;
    }
    #app > div {
      width: 200px;
      height: 80px;
    }
    #app span {
      font-weight: bold;
      font-family: 'Courier New', Courier, monospace;
    }
  </style>
</head>
<body>

<h1>Example: Change Color</h1>

<div id="app">
  <p>Move the mouse pointer over the box below to change the background-color randomly with hsl color code.</p>
  <div v-on:mousemove=" colorVal = Math.floor(Math.random()*360) " v-bind:style=" {backgroundColor: 'hsl('+colorVal+',60%,60%)'} "></div>
  <p><span>backgroundColor: hsl(<strong>{{ colorVal }}</strong>, 80%, 80%)</span></p>
  <p>To understand how to set a color in CSS with 'hsl()' see <a href="/css/css_colors_hsl.asp" target="_blank">our page about this</a>.</p>
</div>

</body>
</html>