CKEditor And HTMLPurifier

Hi! I'm using HTMLPurifier to filter output of CKEditor. I want all format created by CKEditor remains, but without Malicious codes! I used following:

Code:

---

function cleanhtml($htmltext){
        include_once('../include/htmlpurifier/library/HTMLPurifier.auto.php');
        $config = HTMLPurifier_Config::createDefault();
        //$config->set('HTML.TidyLevel', 'medium');
        $config->set('Core.Encoding', 'UTF-8');
        $config->set('HTML.Doctype', 'HTML 4.01 Transitional');
        // Block images coming from remote host
        $config->set('URI.DisableExternalResources', true);
        $config->set('HTML.Trusted', 'true');
       
        // Purify html
        $purifier = new HTMLPurifier($config);
        // get the purified html
        $html = $purifier->purify($htmltext);
        return $html;
}

---

But It removes formatting totally! I want all formats created by CKEditor Preserved (Not Removed). Tables, Spans, Fonts, color...etc

Thank's in advance

I tried appending this line:
$config->set('HTML.Allowed','span[style],table,font');

but all formats still removed even in:
<span style="background-color: rgb(255, 0, 0);">

background color removed!

If anybody have any other method to use CKEditor and the same time protect the website from XSS. Please, tell me the way!
Thank's in advance