Step 2) Add CSS: Example .btn { border: 2px solid black; background-color: white; color: black; padding: 14px 28px; font-size: 16px; cursor: pointer; } /* Green */ .success { border-color: #4CAF50; color: green; } .success:hover { background-color: #4CAF50; color: white; } /* Blue */ .info { border-color: #2196F3; color: dodgerblue } .info:hover { background: #2196F3; color: white; } /* Orange */ .warning { border-color: #ff9800; color: orange; } .warning:hover { background: #ff9800; color: white; } /* Red */ .danger { border-color: #f44336; color: red } .danger:hover { background: #f44336; color: white; } /* Gray */ .default { border-color: #e7e7e7; color: black; } .default:hover { background: #e7e7e7; }