public static function getColorScheme($skinName)
 {
     if (self::$darkSkins === NULL) {
         self::$darkSkins = array();
         $skins = array();
         wfRunHooks('XFBMLSkinColorScheme', array(&$skins));
         foreach ($skins as $skin => $value) {
             if ($value == 'dark') {
                 self::$darkSkins[] = $skin;
             }
         }
     }
     return in_array($skinName, self::$darkSkins) ? 'dark' : 'light';
 }