var background_colours = ["#464646", "#3b3b3b"];

function animate_background()
{
	var colour = background_colours.shift();
	$("body").animate({backgroundColor: colour}, 2000, null, animate_background);
	background_colours.push(colour);
}

$(document).ready(
	function() 
	{
		 var colour = background_colours.shift();
		$("body").css("background-color", colour);
		background_colours.push(colour);
		animate_background();
	 
	}
);