SOURCE

var fade = function(node){
			var level = 1;
			var step = function(){
				var hex = level.toString(16);
				node.style.backgroundColor = '#FFFF' + hex + hex;
				if(level < 15){
					level+=1;
					setTimeout(step,100);
				}
			};
			setTimeout(step,100);
		};

		fade(document.body);