W3Schools Tryit Editor

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
  <style>
  /* Tooltip */
  .test + .tooltip > .tooltip-inner {
    background-color: #73AD21; 
    color: #FFFFFF; 
    border: 1px solid green; 
    padding: 15px;
    font-size: 20px;
  }
  /* Tooltip on top */
  .test + .tooltip.top > .tooltip-arrow {
    border-top: 5px solid green;
  }
  /* Tooltip on bottom */
  .test + .tooltip.bottom > .tooltip-arrow {
    border-bottom: 5px solid blue;
  }
  /* Tooltip on left */
  .test + .tooltip.left > .tooltip-arrow {
    border-left: 5px solid red;
  }
  /* Tooltip on right */
  .test + .tooltip.right > .tooltip-arrow {
    border-right: 5px solid black;
  }
  </style>
</head>
<body>

<div class="container">
  <h3>Tooltip CSS Example</h3>
  <ul class="list-inline">
    <li><a class="test" href="#" data-toggle="tooltip" data-placement="top" title="Hooray!">Top</a></li>
    <li><a class="test" href="#" data-toggle="tooltip" data-placement="bottom" title="Hooray!">Bottom</a></li>
    <li><a class="test" href="#" data-toggle="tooltip" data-placement="left" title="Hooray!">Left</a></li>
    <li><a class="test" href="#" data-toggle="tooltip" data-placement="right" title="Hooray!">Right</a></li>
  </ul>
</div>

</body>
</html>