Preparing for Dark mode theme: Started Fixing models so they look better in dark mode

ajax/ajax_admin_mail_queue_message_view.php

@@ -43,13 +43,13 @@ if ($email_status == 0) {
 // Generate the HTML form content using output buffering.
 ob_start();
 ?>
-<div class="modal-header">
+<div class="modal-header bg-dark">
     <h5 class="modal-title"><i class='fas fa-fw fa-envelope-open mr-2'></i><strong><?php echo $email_subject; ?></strong></h5>
-    <button type="button" class="close text-white" data-dismiss="modal">
+    <button type="button" class="close text-light" data-dismiss="modal">
         <span>&times;</span>
     </button>
 </div>
-<div class="modal-body bg-white">
+<div class="modal-body">
     <div class="row">
         <div class="col-md-1">
             <span class="text-secondary">From:</span>