Different backgrounds

Hi,
on my site I am trying to achieve the following but don’t know how.

I want to have a background on the content area, while leaving the sidebar with a white background. I tried Theme options -> General styling -> Main Content -> and when I choose a background image there that goes to main content and sidebar.

However, I want something different. I want to have another background showing on the content (not the sidebar), BUT I want different images to as backgrounds to different pages. I was thinking about colour sections, but these do not display the sidebar. Please look at my site, you will understand what I mean.

Kind regards,
Ioannis