<!DOCTYPE html>
<html>
<head>
<style>
p.ex1 {
border: 1px solid red;
outline-style: solid;
outline-color: invert;
}
</style>
</head>
<body>
<h2>Using outline-color:invert</h2>
<p class="ex1">A solid invert outline.</p>
</body>
</html>