adjust custom menu widget width in custom theme

I’m using Colr theme with my website (www.seankennedy.org) and I’m very happy with it, but I have a quick question. I have a custom menu widget in the sidebar, which as you can see, gives me a nice simple menu from which to navigate the site. I just added the “bio” page and in doing so had to increase the column width and margin in the theme options. The issue I’m having is that this also increases the width of the sidebar menu, which pushes the images nearly off the right side of the screen when you click on any of the page links. Before adjusting these settings, for instance, the image on the homepage with the Monster energy logos was much more centered left to right on the screen. Now that column width is bumping it over to the right. So, my question is, can I keep the column width as it is and reduce the width of the sidebar menu?

Thanks in advance for your help.