代码示例:(标识:bs_utility_borders_colors)
<!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 href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/css/bootstrap.min.css" rel="stylesheet">
  <script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/js/bootstrap.bundle.js"></script>
  <style>
  .border {
    display: inline-block;
    width: 70px;
    height: 70px;
    margin: 6px;
  }
  </style>
</head>
<body>

<div class="p-4">
  <h2>边框颜色</h2>
  <p>请使用任意上下文边框颜色类向边框添加颜色:</p> 
  <span class="border border-primary"></span>
  <span class="border border-secondary"></span>
  <span class="border border-success"></span>
  <span class="border border-danger"></span>
  <span class="border border-warning"></span>
  <span class="border border-info"></span>
  <span class="border border-light"></span>
  <span class="border border-dark"></span>
  <span class="border border-white"></span>
</div>

</body>
</html>
运行结果: