Really fix background color on 480x800 theme

Change-Id: I70324ae3e4fffe88bc2b5a02becb7d1f4f0ceab0
diff --git a/gui/devices/480x800/res/ui.xml b/gui/devices/480x800/res/ui.xml
index 0d41c41..341332f 100644
--- a/gui/devices/480x800/res/ui.xml
+++ b/gui/devices/480x800/res/ui.xml
@@ -213,6 +213,8 @@
 
 	<templates>
 		<template name="header">
+			<background color="#000000FF" />
+
 			<object type="fill" color="%button_fill_color%">
 				<placement x="0" y="0" w="480" h="98" />
 			</object>