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>