Add user role name to body tag as class

functions.php

<?php

// Add user role as body class
function print_user_classes() {
	add_filter('body_class','class_to_body');
}
add_action('init', 'print_user_classes');

// Add user role class to front-end body tag
function class_to_body($classes) {
	if ( is_user_logged_in() ) {
		global $current_user;

		$user_role = array_shift($current_user->roles);
		$classes[] = $user_role . ' ';
	} else{
		$classes[] = 'loggedout-product-class';
	}

	return $classes;
}

?>