Now I remember what my problem with the 2col.color.beta layout was. The background color thing works fine unless you want to have a footer that runs the width of the page, on top of those two columns of color, with its own background color.
The problem happens when your browser viewport is taller than the content. The color columns will go the full height of the page while the footer will wind up being rendered say half-way down the viewport. But those colors will pop out below the footer and keep going down.
So the trick is to find a way to put the footer at the bottom of the content OR window, whichever is taller.