Index: wp-admin/css/customize-controls.dev.css
===================================================================
--- wp-admin/css/customize-controls.dev.css	(revision 20980)
+++ wp-admin/css/customize-controls.dev.css	(working copy)
@@ -92,11 +92,6 @@
 	display: none;
 }
 
-.customize-section.open .customize-section-title:after {
-	margin-top: -1px;
-	border-width: 0 6px 6px;
-}
-
 .customize-section-title:hover:after {
 	border-color: #aaa transparent;
 }
Index: wp-admin/css/wp-admin.dev.css
===================================================================
--- wp-admin/css/wp-admin.dev.css	(revision 20980)
+++ wp-admin/css/wp-admin.dev.css	(working copy)
@@ -5288,7 +5288,7 @@
 	margin: 0;
 	z-index: 10;
 	overflow: auto;
-	background: #f5f5f5;
+	background: #f8f8f8;
 	border-right: 1px solid rgba( 0, 0, 0, 0.2 );
 }