Remove default stylesheets from frontend WordPress

functions.php

// remove auto stylesheet from admin + wp
add_action( 'wp_print_styles',     'my_deregister_styles', 100 );
function my_deregister_styles()    {
   wp_deregister_style( 'dashicons' );
   wp_deregister_style( 'admin-bar' );
   wp_deregister_style( 'open-sans' );
   wp_deregister_style( 'boxes' );
}