Background won’t show in some emails

Hi. I’ve tried everything I can think of to get the background of my email designs to show — but no success. When I design them in Outlook, then send to Yahoo, they show up fine. But no way in Hotmail. I see only the graphics that I embedded, added, stuck on/into the email. But the background color that I add in Word or FrontPage doesn’t show. All I see is a white background. Anybody know what to do? Thanks.