Reset background page color - outside of webpage width

I just realized that I'm not able to customize the "page" color (outside the width of the webpage) myself on an established page. Can you verify this is true? And if yes, is someone at Homestead able to do this for me?

Some templates have full-width colors and others don't. I didn't realize I couldn't change it until now. My site is highly customized - choosing a new template isn't a great option at this point. Help?

website in question: www.laiventures.com

PS Site is already live and changes are in mid- process, so if you view the site, please don't publish anything!