HTML

bootstrap modal is grayed out

/*grayed modal*/

.modal-backdrop {
    display: none;
    z-index: 1040 !important;
}

bootstrap modal remove gray background

<!-- Button trigger modal -->
<button type="button" class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal" data-backdrop="false">
  Launch demo modal
</button>

bootstrap modal remove gray background

$('.modal-backdrop').remove();