Add layout to Twenty Eleven

I’m using this https://pastebin.com/xn73rcKj to add extra color schemes to a Twenty Eleven child theme, I took a look at theme options but I can’t figure out how to add extra layouts.

I also don’t understand how these layouts are configured. For the color schemes there’s a dark.css, but I don’t see anything relating to sidebar left, sidebar right, single column liek Twenty Ten would have.