var hexChars = "23456789ABCDEFFF";

function Dec2Hex (Dec) {
if ( Dec > 255 ) {
		hex = "ff";
	} else {
		var a = Dec % 16;
		var b = (Dec - a)/16;
		hex = "" + hexChars.charAt(b) + hexChars.charAt(a);
	}
  return hex;
};

function colorshift(e) {
//	window.alert( e.pageX + ' '  + e.pageY );
//  document.bgColor = "#" + Dec2Hex(window.innerWidth-e.pageX/1) + Dec2Hex(window.innerHeight-e.pageY/1) + Dec2Hex((window.innerWidth-e.pageX-e.pageY));
  document.bgColor = "#" + Dec2Hex(255-((e.pageX/window.innerWidth)*255)) + Dec2Hex(255-((e.pageY/window.innerHeight)*255)) + Dec2Hex((e.pageX+e.pageY));
}

window.captureEvents(Event.MOUSEMOVE);
window.onmousemove = colorshift;