In the spirit of 'teach a man to fish", I'm going to suggest that you install the Firefox browser and the Web Devloper plugin. Then open your site in Firefox, and CTRL-SHIFT-Y will allow you to hover over the area you're interested in, and you'll see the applicable CSS in the box at the top. CTRL-SHIFT-E will open the CSS editor, where you can make test changes that will be reflected immediately in your page. A very handy tool.

Also, the Colorzilla plugin for Firefox will allow you to put your mouse pointer on an area and see what color it's using. I use both these tools constantly.

The sidebox 'footers' are borders. Search the stylesheet for 'border' until, you find the ones you're looking for.