Hide Admin Menu Items for a Custom User Role

/**
 * Clone the administrator user role
 */
function clone_admin_role() {
    global $wp_roles;
    if ( ! isset( $wp_roles ) )
        $wp_roles = new WP_Roles();
    
    $adm = $wp_roles->get_role( 'administrator' );
    
    // Add new "Client" role with all admin capabilities
    $wp_roles->add_role( 'client', 'Client', $adm->capabilities );
}

add_action( 'init', 'clone_admin_role' );

/**
 * Specify which admin menu items are visible for users with role "Client"
 */
function remove_dashboard_menus() {
    if ( current_user_can( 'client' ) ) {
        // Hide Updates under Dashboard menu
        remove_submenu_page( 'index.php', 'update-core.php' );

        // Hide Comments
        remove_menu_page( 'edit-comments.php' );

        // Hide Plugins
        remove_menu_page( 'plugins.php' );

        // Hide Themes, Customizer and Widgets under Appearance menu
        remove_submenu_page( 'themes.php', 'themes.php' );
        remove_submenu_page( 'themes.php', 'customize.php?return=' . urlencode( $_SERVER['REQUEST_URI'] ) );
        remove_submenu_page( 'themes.php', 'widgets.php' );

        // Hide Tools
        remove_menu_page( 'tools.php' );

        // Hide General Settings
        remove_menu_page( 'options-general.php' );
    }
}

add_action( 'admin_menu', 'remove_dashboard_menus' );