Sortable custom userfields in backend

<?php // USER FILTER
	function wpse_user_sortable_columns($columns) {
    $columns['Genre'] = 'Genre';
    $columns['Color'] = 'Color';
    return $columns;
}
add_filter('manage_users_sortable_columns', 'wpse_user_sortable_columns');

It does make the column title clickable and it is kind of switching when clicking it. But the result makes no sense. Its neither ASC & DESC nor date % title.

Where am i wrong?