--- a/pylib/mozreview/mozreview/static/mozreview/css/mozilla-theme.less
+++ b/pylib/mozreview/mozreview/static/mozreview/css/mozilla-theme.less
@@ -264,8 +264,32 @@ body.datagrid-page {
   .filename-row th {
     background: @moz-blue-dark;
   }
 
   .revision-row th .rb-icon {
     vertical-align: sub;
   }
 }
+
+/* Dialogs */
+.modalbox-inner, .modalbox-title, .modalbox {
+  background-image: none;
+  .border-radius(0);
+}
+
+.modalbox-title {
+  background: @moz-blue-dark;
+  border-bottom-color: #888a85;
+}
+
+.modalbox-inner {
+  background: @moz-blue-light;
+}
+
+.modalbox-bg {
+  background: rgba(255, 255, 255, 0.6) !important; /* overriding JS */
+}
+
+/* Comment Dialogs */
+.comment-dlg {
+  .border-radius(0);
+}