katamason,
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>tooltip demo</title>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.11.0/themes/smoothness/jquery-ui.css">
<script src="http://code.jquery.com/jquery-1.10.2.js"></script>
<script src="http://code.jquery.com/ui/1.11.0/jquery-ui.js"></script>
<style type="text/css">
.myclass {
background: #FFFF00;
}
</style>
</head>
<body>
<p>
<a href="#" title="Anchor description">Anchor text</a>
<input title="Input help">
</p>
<script>
$( document ).tooltip({ tooltipClass:"myclass" });
</script>
</body>
</html>