--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -497,22 +497,20 @@ toolbar:not(#TabsToolbar) > #personal-bo
 #PopupAutoComplete > richlistbox > richlistitem > .ac-separator,
 #PopupAutoComplete > richlistbox > richlistitem > .ac-url {
   display: none;
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] {
   -moz-binding: url("chrome://global/content/bindings/autocomplete.xml#autocomplete-richlistitem-insecure-field");
   height: auto;
-  background-color: #F6F6F6;
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] > .ac-site-icon {
   display: initial;
-  list-style-image: url(chrome://browser/skin/connection-mixed-active-loaded.svg#icon);
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] > .ac-title > .ac-text-overflow-container > .ac-title-text {
   text-overflow: initial;
   white-space: initial;
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] > .ac-title > label {

--- a/browser/themes/shared/autocomplete.inc.css
+++ b/browser/themes/shared/autocomplete.inc.css
@@ -15,8 +15,17 @@
 #PopupAutoComplete > richlistbox > richlistitem > .ac-title {
   font: icon;
   margin-inline-start: 6px;
 }
 
 #PopupAutoComplete > richlistbox {
   padding: 0;
 }
+
+/* Insecure field warning */
+#PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] {
+  background-color: #F6F6F6; /* Bug 1319176 */
+}
+
+#PopupAutoComplete > richlistbox > richlistitem[originaltype="insecureWarning"] > .ac-site-icon {
+  list-style-image: url(chrome://browser/skin/connection-mixed-active-loaded.svg#icon);
+}