How to Improve WMS Image Quality?

[Bill Thoen]

After getting my last message swamped by an out-of-control 
autoresponder, I thought I'd better try again. So here's my question again:

I've linked DOQ images from the Microsoft TerraServer's WMS, but they look
terrible in my MapServer map. It looks like they are being rendered in
8-bit grayscale. When I display these same images with a GetMap URL in my
browser they look fine. Could someone tell me what I need to do to get
these to look better in MapServer?