Timid,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(function(){
var i = 0, bgcolors = ["#FFFFCC", "#CCFFCC", "#FFCCCC", "#DCDCDC", "#FFCC99", ""] ;
$(".bg_fon").click(function () {
$("body").css({"backgroundColor" : bgcolors[i++ % bgcolors.length]});
});
});
</script>
</head>
<body>
<a href="#" class="bg_fon">Изменить фон</a>
</body>
</html>