代码示例:(标识:css_outline-color-hsl)
<!DOCTYPE html>
<html>
<head>
<style>
p.ex1 {
  border: 2px solid black;
  outline-style: solid;
  outline-color: hsl(0, 100%, 50%); /* red */
}

p.ex2 {
  border: 2px solid black;
  outline-style: dotted;
  outline-color: hsl(240, 100%, 50%); /* blue */
}

p.ex3 {
  border: 2px solid black;
  outline-style: solid;
  outline-color: hsl(0, 0%, 73%); /* grey */
}
</style>
</head>
<body>

<h1>outline-color 属性</h1>
<p>也可以使用 HSL 值规定轮廓颜色:</p>

<p class="ex1">红色的实线轮廓。</p>
<p class="ex2">蓝色的点状轮廓。</p>
<p class="ex3">灰色的实线轮廓。</p>

</body>
</html>
运行结果: