sudo cp /usr/share/software-center/ui/gtk3/css/softwarecenter.css /usr/share/software-center/ui/gtk3/css/softwarecenter.css.Original
sudo cp /usr/share/software-center/ui/gtk3/art/stipple.png /usr/share/software-center/ui/gtk3/art/stipple.png.Original
sudo cp /usr/share/themes/delorean-light-theme-3.6/Software-Center/softwarecenter.css /usr/share/software-center/ui/gtk3/css/softwarecenter.css
sudo cp /usr/share/themes/delorean-light-theme-3.6/Software-Center/stipple.png /usr/share/software-center/ui/gtk3/art/stipple.png
I can send you a picture with the type of menus I refer to. For instance, if you open VLC and go to tools->preferences you get a new Window. In there is an option menu called "Force Window Style". If you click there any option is invisible. You have to put the mouse over each of them to make them visible.
It is a shame, but it matches decently and everything is performing well now.
running ubuntu-12.04 and Cinnamon.