Access specific node (custom_field) simplexml - parsing

Question

This XML file, which can be accessed here # http://afdclinics.com/persistentpresence/category/brentwood/lobby-1/feed/ - has a custom_fields node with 2 fields called custom-bgcolor, and custom-fontcolor. I have tried numerous ways to try, and access the data inside them with no luck.
I have been accessing other nodes with simplexml, but haven't been able to get the custom_fields working. Here is what I have so far.
$curl = curl_init();
curl_setopt ($curl, CURLOPT_URL,'http://afdclinics.com/persistentpresence/category/brentwood/lobby-1/feed/');
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec ($curl);
if ($result === false) {
die('Error fetching data: ' . curl_error($curl));
}
curl_close ($curl);
//we can at this point echo the XML if you want
//echo $result;
//parse xml string into SimpleXML objects
$xml = simplexml_load_string($result);
if ($xml === false) {
die('Error parsing XML');
}
//now we can loop through the xml structure
foreach ($xml->channel->item as $item) {
//print $item->title; rss feed article title
//print $item->description; rss feed article description
//print $item->link; rss feed article link
//print $item->pubDate; rss feed article publish date
print $item->children('content', true); //rss feed article content
// here is where is would like to print the custom values
print $item->custom_fields->custom-bgcolor; // this line doesn't seem to work
//gets img url's and appends them to offline manifest file
$imgUrl = array();
$doc2 = new DOMDocument();
$doc2->loadHTML($item->children('content', true));
$imgUrl = simplexml_import_dom($doc2);
$images = $imgUrl->xpath('//img');
foreach ($images as $img) {
$imgUrl = $img['src'] . "\r\n";
print $imgUrl; //rss feed image url's
$i++;
}