<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> <!------ Include the above in your HEAD tag ----------> <!-- Modal --> <div class="modal modal-primary fade" id="exampleModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true"> <div class="modal-dialog"> <div class="modal-content"> <div class="modal-header"> <h5 class="modal-title" id="exampleModalLabel">Modal title</h5> </div> <div class="modal-body"> ... </div> </div> </div> </div> <!-- Button trigger modal --> <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal"> Launch demo modal </button>

.modal-primary .modal-header { background: var(--primary); color: white; border: 0; }