Use .label-danger class in Bootstrap to add red colored label.
You can try to run the following code to implement the .label-danger class −
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet"> <script src = "/scripts/jquery.min.js"></script> <script src = "/bootstrap/js/bootstrap.min.js"></script> </head> <body> <div class = "container"> <p>If you find any issues, click below</p> <span class = "label label-danger">Danger</span> </div> </body> </html>