Index: src/wp-admin/css/customize-controls.css
===================================================================
--- src/wp-admin/css/customize-controls.css	(revision 51499)
+++ src/wp-admin/css/customize-controls.css	(working copy)
@@ -1565,6 +1565,10 @@
 	display: block;
 }
 
+.background-position-control .button-group input[type="radio"]:focus{
+	display: none;
+}
+
 /**
  * Code Editor Control and Custom CSS Section
  *