I have not been able. I have not been able o either change the colour of the background to e-mails

Question

I have not been able o either change the colour of the background to e-mails from "outlook express" or place a picture as a background. Having sent e-mails to myself and tried to change the background for a picture what I get back is a picture as an attachment. My e-mails are set to HTML. I think some recipients get the mail as I intend it, but it does not show on my system.