--- a/browser/themes/shared/autocomplete.inc.css
+++ b/browser/themes/shared/autocomplete.inc.css
@@ -35,14 +35,30 @@
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="login"] > .ac-site-icon[selected] {
   list-style-image: url(chrome://browser/skin/notification-icons.svg#login-highlighted);
 }
 
 
 /* Insecure field warning */
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] {
-  background-color: #F6F6F6; /* Bug 1319176 */
+  background-color: var(--arrowpanel-dimmed);
+  border-bottom: 1px solid var(--panel-separator-color);
+  padding-bottom: 4px;
+  padding-top: 4px;
+}
+
+#PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"][selected] {
+  background-color: var(--arrowpanel-dimmed-further);
+}
+
+#PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] > .ac-title {
+  color: GrayText;
+  font-size: 1em;
+}
+
+#PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"][selected] > .ac-title {
+  color: inherit;
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] > .ac-site-icon {
   list-style-image: url(chrome://browser/skin/connection-mixed-active-loaded.svg#icon);
 }