Online PHP editor | refs for A3TAR

<?php $palette = ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet']; $count = count($palette); echo preg_replace_callback( '~\PZ~u', function ($m) use($palette, $count) { static $i = 0; return sprintf('<span style="color:%s">%s</span>', $palette[$i++ % $count], $m[0]); }, 'Stack Overflow volunteerism' );