Index: /trunk/src/VBox/Frontends/VirtualBox/src/widgets/VBoxMiniToolBar.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/widgets/VBoxMiniToolBar.cpp	(revision 35063)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/widgets/VBoxMiniToolBar.cpp	(revision 35064)
@@ -126,4 +126,7 @@
     /* Enable mouse-tracking for this & children allowing to get mouse-move events: */
     setMouseTrackingEnabled(m_fAutoHide);
+
+    /* Auto-fill background to make it use own color: */
+    setAutoFillBackground(true);
 }