AdminLte/build/scss/_modals.scss

/*
 * General: Modals
 * ----------------------
 */

// Overlay
.modal-dialog {
  .overlay {
      display: block;
      position: absolute;
      z-index: ($zindex-modal + 2);
      background: rgba(255, 255, 255, 0.7);
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
  }
}

// BG Color Variations Fixes
.modal-content {
  &.bg-warning {
    .modal-header,
    .modal-footer {
      border-color: $gray-800;
    }
  }
}
.modal-content {
  &.bg-primary,
  &.bg-secondary,
  &.bg-info,
  &.bg-danger,
  &.bg-success, {
    .close{
      color: $white;
    }
  }
}