--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -754,16 +754,17 @@ BrowserGlue.prototype = {
       description: gBrowserBundle.GetStringFromName("darkTheme.description"),
       iconURL: "resource:///chrome/browser/content/browser/defaultthemes/dark.icon.svg",
       textcolor: "white",
       accentcolor: "black",
       popup: "#4a4a4f",
       popup_text: "rgb(249, 249, 250)",
       popup_border: "#27272b",
       toolbar_field_text: "rgb(249, 249, 250)",
+      toolbar_field_border: "rgba(249, 249, 250, 0.2)",
       author: vendorShortName,
     });
 
     Normandy.init();
 
     // Initialize the default l10n resource sources for L10nRegistry.
     let locales = Services.locale.getPackagedLocales();
     const appSource = new FileSource("app", locales, "resource://app/localization/{locale}/");

--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -45,17 +45,21 @@
   --toolbar-bgimage: none;
 
   --toolbox-border-bottom-color: rgba(0,0,0,.3);
 
   --panel-separator-color: hsla(210,4%,10%,.14);
 }
 
 :root[lwt-popup-brighttext] {
-  --panel-separator-color: hsla(0,0%,80%,.25);
+  --panel-separator-color: rgba(249,249,250,.2);
+
+  --arrowpanel-dimmed: rgba(249,249,250,.1);
+  --arrowpanel-dimmed-further: rgba(249,249,250,.15);
+  --arrowpanel-dimmed-even-further: rgba(249,249,250,.2);
 }
 
 #menubar-items {
   -moz-box-orient: vertical; /* for flex hack */
 }
 
 #main-menubar {
   -moz-box-flex: 1; /* make menu items expand to fill toolbar height */

--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -36,17 +36,21 @@
 :root:-moz-lwtheme {
   --toolbar-bgcolor: rgba(255,255,255,.4);
   --toolbar-bgimage: none;
 
   --toolbox-border-bottom-color: rgba(0,0,0,.3);
 }
 
 :root[lwt-popup-brighttext] {
-  --panel-separator-color: hsla(0,0%,80%,.25);
+  --panel-separator-color: rgba(249,249,250,.2);
+
+  --arrowpanel-dimmed: rgba(249,249,250,.1);
+  --arrowpanel-dimmed-further: rgba(249,249,250,.15);
+  --arrowpanel-dimmed-even-further: rgba(249,249,250,.2);
 }
 
 #navigator-toolbox {
   --tabs-border-color: rgba(0,0,0,.3);
 }
 
 #tabbrowser-tabs {
   --tab-line-color: #0a84ff;

--- a/browser/themes/shared/compacttheme.inc.css
+++ b/browser/themes/shared/compacttheme.inc.css
@@ -25,16 +25,21 @@
   --chrome-nav-bar-controls-border-color: hsla(240, 5%, 5%, .3);
   --chrome-selection-color: #fff;
   --chrome-selection-background-color: #5675B9;
 
   /* Url and search bars */
   --lwt-toolbar-field-background-color: rgb(71, 71, 73);
   --lwt-toolbar-field-color: var(--chrome-color);
   --urlbar-separator-color: #5F6670;
+
+  /* !important to override LightweightThemeManager.addBuiltInTheme in
+     nsBrowserGlue.js */
+  --autocomplete-popup-background: #2A2A2E !important;
+  --autocomplete-popup-highlight-background: #0060DF;
 }
 
 :root:-moz-lwtheme-darktext {
   --lwt-toolbar-field-background-color: #fff;
 
   --chrome-background-color: #E3E4E6;
   --chrome-color: #18191a;
   --chrome-secondary-background-color: #f5f6f7;

--- a/browser/themes/shared/searchbar.inc.css
+++ b/browser/themes/shared/searchbar.inc.css
@@ -47,16 +47,20 @@
   font-weight: normal;
   background-color: var(--arrowpanel-dimmed);
   border-top: 1px solid var(--panel-separator-color);
   margin: 0;
   padding: 3px 6px;
   color: var(--panel-disabled-color);
 }
 
+:root[lwt-popup-brighttext] .search-panel-header {
+  color: var(--autocomplete-popup-color);
+}
+
 .search-panel-header > label {
   margin-top: 2px !important;
   margin-bottom: 1px !important;
 }
 
 .search-panel-current-input > label {
   margin: 2px 0 !important;
 }

--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -67,17 +67,21 @@
   --toolbar-bgimage: none;
 
   --toolbox-border-bottom-color: rgba(0,0,0,.3);
 
   --panel-separator-color: hsla(210,4%,10%,.14);
 }
 
 :root[lwt-popup-brighttext] {
-  --panel-separator-color: hsla(0,0%,80%,.25);
+  --panel-separator-color: rgba(249,249,250,.2);
+
+  --arrowpanel-dimmed: rgba(249,249,250,.1);
+  --arrowpanel-dimmed-further: rgba(249,249,250,.15);
+  --arrowpanel-dimmed-even-further: rgba(249,249,250,.2);
 }
 
 #navigator-toolbox:-moz-lwtheme {
   --tabs-border-color: rgba(0,0,0,.3);
 }
 
 #menubar-items {
   -moz-box-orient: vertical; /* for flex hack */