HTML/CSS/Box Model/border color
border-color: black
<html>
<head>
<title>Box Model Basics</title>
<style>
body {font-size: 1.5em;}
p {background-color: white;
text-align: center;
border-color: black;
border-style: solid;}
</style>
</head>
<body>
<p>the <p> element.</p>
<p>second <p> element.</p>
</body>
</html>