How to add a strip of color in the background? Montauk

I'm wanting to add a strip of colour behind some of my content on my site.

I am trying to achieve this:alt text

My site currently looks like this:alt text

I have set up the main content using a combination of text blocks, spacers and markdown blocks.

Any help would be much appreciated as I have no idea how to do this! Or if it is even possible with the Montauk template.

Thank you in advanceNatalia

Edited May 18, 2015 by nataliasavannah

Hi. Can you send some images? We don't see any.