I’m using the following external CSS files:
<link href="/jquery_custom/green/jquery-ui-1.8.16.custom.css" rel="stylesheet" type="text/css" />
<link href="/jquery_custom/css/blue/jquery-ui-1.8.7.custom.css" rel="stylesheet" type="text/css" /></script>
And JavaScript:
<script language = "javascript" type="text/javascript">
$(document).ready(function () {
$("button").button();
});
</script>
I have noticed on the jQuery UI site there is an Advanced option:

What do I need to do to have more than one style one the page? Including the two separate external ui-custom js files cause problems. And I notice Facebook has two different colored buttons:

How can this be done?
You mean have different colors/styles for each button? You can do that with just CSS, like so:
CSS
HTML
Demo