<style type="text/css">
	.default{
		border: 1px solid #000;
		margin: 3px;
		width: 250px;
		height: 80px;
		float: left;
		font: 10px verdana;
		text-align: center;
		color: #fff;
	}
</style>

<div style="width: 780px; margin: auto;">
<script type="text/javascript">
//<![CDATA[
	for(var i = 2 * 3, c; i--;) // #990000 - #ff0000 // RED
		document.write("<div class='default' style='background:" + (c = RGBRandom("990000", "ff0000")) + ";'>" + c + "</div>");
	for(var i = 2 * 3, c; i--;) // #009900 - #00ff00 // GREEN
		document.write("<div class='default' style='background:" + (c = RGBRandom("009900", "00ff00")) + ";'>" + c + "</div>");
	for(var i = 2 * 3, c; i--;) // #000099 - #0000ff // BLUE
		document.write("<div class='default' style='background:" + (c = RGBRandom("000099", "0000ff")) + ";'>" + c + "</div>");
	for(var i = 2 * 3, c; i--;) // #cccccc - #ffffff
		document.write("<div class='default' style='color:#000;background:" + (c = RGBRandom("cccccc", "ffffff")) + ";'>" + c + "</div>");
//]]>
</script>
</div>