1.
$str='afdsadsfhong"名字"normalafdsadsf';
$str=preg_replace("/hong\"(.+)\"normal/im","<font color=red>\\1</font>",$str);
echo $str;2.
$STR='AAAAhei"名"hong"字"normalAAAAAA';
$STR=preg_replace("/hei\"(.+)\"hong\"(.+)\"normal/im","<font color=black>\\1</font><font color=red>\\2</font>",$STR);
echo $STR;