layout.full class

Hey, I’m wondering if you can shed some light on exactly what this .layout-full class does. Essentially as it stands, I have page background image that I want to stop at the footer #colophon. So this works, but on pages with little content, I see a large dark grey rectangle with the class .layout-full sitting below the footer. I can’t for the life of me figure out what this is for, but it prevents my footer from looking correct when positioned absolutely at the bottom of the page. Is there a way to remove it?