I don't think you can change the bgcolor of a cell.

BUT, wait, don't go away just yet!

With IE4 you can change the background picture of a cell.

I don't think this is possible with NS though.

So, all you need is 2 small GIFs the required colours and this code:


Code:
<html>

<body>

<TABLE><TR>
<TD ID="td1" onMouseover="document.all.td1.background='blue.gif'" onMouseout="document.all.td1.background='red.gif'" background='red.gif'>hello</TD>
<TD ID="td2" onMouseover="document.all.td2.background='blue.gif'" onMouseout="document.all.td2.background='red.gif'" background='red.gif'>hello</TD>
</TR><TR>
<TD ID="td3" onMouseover="document.all.td3.background='blue.gif'" onMouseout="document.all.td3.background='red.gif'" background='red.gif'>hello</TD>
<TD ID="td4" onMouseover="document.all.td4.background='blue.gif'" onMouseout="document.all.td4.background='red.gif'" background='red.gif'>hello</TD>
</TR></TABLE>
</body
</html>