Track background colors no longer change after saving settings.

visual/src/main/webapp/resources/eventSettings.js

@@ -4,6 +4,7 @@ const settingsUpdatedChannel = new BroadcastChannel("settings_updated");
 settingsUpdatedChannel.onmessage = function(ev) {
     if (recording_id != null) {
         clearList();
+        window.countColor = 0;
         drawGraph();
     }
 };