Index: wp-admin/css/colors-fresh.css
===================================================================
--- wp-admin/css/colors-fresh.css	(revision 8766)
+++ wp-admin/css/colors-fresh.css	(working copy)
@@ -456,6 +456,10 @@
 	background-image: url(../images/toggle-arrow.gif);
 }
 
+#poststuff .postbox {
+	background-color: #FFF;
+}
+
 #quicktags #ed_link {
 	color: #00f;
 }
Index: wp-admin/css/colors-classic.css
===================================================================
--- wp-admin/css/colors-classic.css	(revision 8766)
+++ wp-admin/css/colors-classic.css	(working copy)
@@ -471,6 +471,10 @@
 	background-image: url(../images/toggle-arrow.gif);
 }
 
+#poststuff .postbox {
+	background-color: #FFF;
+}
+
 #quicktags #ed_link {
 	color: #00f;
 }