--- a/browser/themes/shared/urlbar-searchbar.inc.css
+++ b/browser/themes/shared/urlbar-searchbar.inc.css
@@ -33,16 +33,22 @@
   box-shadow: 0 1px 4px rgba(0,0,0,.05);
   padding: 0;
   margin: 3px 5px;
   min-height: 30px;
   cursor: default;
   overflow: -moz-hidden-unscrollable;
 }
 
+:root[lwt-toolbar-field-brighttext] #urlbar *|*::selection,
+:root[lwt-toolbar-field-brighttext] #navigator-toolbox .searchbar-textbox *|*::selection {
+  background-color: Highlight;
+  color: HighlightText;
+}
+
 #urlbar:hover,
 .searchbar-textbox:hover {
   border-color: @fieldHoverBorderColor@;
   box-shadow: 0 1px 6px rgba(0,0,0,.1);
 }
 
 #urlbar:-moz-lwtheme,
 #navigator-toolbox .searchbar-textbox:-moz-lwtheme {

--- a/toolkit/themes/shared/findBar.inc.css
+++ b/toolkit/themes/shared/findBar.inc.css
@@ -60,16 +60,21 @@ findbar[noanim] {
   width: 14em;
 }
 
 .findbar-textbox:-moz-lwtheme {
   background-color: var(--lwt-toolbar-field-background-color, -moz-Field);
   color: var(--lwt-toolbar-field-color, -moz-FieldText);
 }
 
+:root[lwt-toolbar-field-brighttext] .findbar-textbox *|*::selection {
+  background-color: Highlight;
+  color: HighlightText;
+}
+
 .findbar-textbox:-moz-locale-dir(ltr) {
   border-top-right-radius: 0;
   border-bottom-right-radius: 0;
 }
 
 .findbar-textbox:-moz-locale-dir(rtl) {
   border-top-left-radius: 0;
   border-bottom-left-radius: 0;