问如何在echo里面改变PHP中变量的字体颜色？

<?php   
$dir = "./";   
$Color = "red";

// Open a known directory, and proceed to read its contents   
if (is_dir($dir)) {   
   if ($dh = opendir($dir)) {   

       while (($file = readdir($dh)) !== false) {   
       if ($file!="." && $file!="..") {   
       echo "<a href=./".$file.">".$file."</a><br>";   
       }   
       }   
       closedir($dh);   
   }   
}   
?>