diff --git a/www/js/app.js b/www/js/app.js
index 184f1653..a91aa53f 100644
--- a/www/js/app.js
+++ b/www/js/app.js
@@ -2252,10 +2252,13 @@ define(['jquery', 'zimArchiveLoader', 'uiUtil', 'util', 'utf8', 'cache', 'images
                 });
             });
             var scrollbox = document.getElementById('scrollbox');
+            var prefix = document.getElementById('prefix');
             if (params.appCache) {
                 scrollbox.style.removeProperty('background');
+                prefix.style.removeProperty('background');
             } else {
-                scrollbox.style.background = cssUIThemeGetOrSet(params.cssUITheme, true) === 'dark' ? 'maroon' : 'mistyrose';
+                scrollbox.style.background = /^dark/.test(document.body.className) ? '#300000' : 'mistyrose';
+                prefix.style.setProperty('background', /^dark/.test(document.body.className) ? '#200000' : 'lavenderblush', 'important');
             }
             var expertSettings = document.getElementById('expertSettingsDiv');
             expertSettings.classList.remove('panel-warning');