rockerror,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
div{
width: 408px;
height: 30px;
background-color: #00FF00;
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<script>
$(function ()
{
$('div').animate({
backgroundColor:'#ff0000' // цвет тут просто для примера
},5000);
})
</script>
</head>
<body>
<div></div>
</body>
</html>