Trouble putting a border around my page content?

[dreamcon]

Hi there,

Can someone please help me with a theming problem.

I want to put a border around me page content. I have just the content section with a white background and the rest of the site sections have background colour. I think it would look better with a border around the white section.

I have tried selecting this in the themebuilder - I have selected Content which seems to pick up this section fully and have gone to the borders tab and selected a border type from the dropdown and the colour but nothing happens?

Could someone tell me what I'm doing wrong and how to do this?

Many thanks