求助一个问题！！！！

<ul id="blogtags"> 
<?php shuffle($tag_cache);foreach($tag_cache as $value): $color = dechex(rand(0,16777215));?> 
<span style="font-size:16px;background-color:#<?php echo $color;?>;line-height:21px;"> 
<a href="<?php echo Url::tag($value['tagurl']); ?>"   title="<?php echo $value['usenum']; ?> 篇日志"><?php echo $value['tagname']; ?></a> 
</span> 
<?php endforeach; ?> 
</ul>