Why is the following code resets the background to white color while i have defined it black?

Code:
<html>
	<head>
		<title>Test Page</title>
	</head>
		
	<body bgcolor="#000000" text="#00ff00">
		<font face="system">
		
		<script language="javascript">
		<!--
			var i;
			var timer = 0;
			var speed = 500;
			var mytext = "Hello World...";
			
			document.write("<b>");
				
			for (i = 0; i <= mytext.length; i++) 
			{
				timer += (Math.random() * speed);
				setTimeout("document.write('" + mytext.charAt(i) + "');", timer);
			}
			
			document.write("</b>");
		-->
		</script>
		
		</font>
	</body>
</html>