Go in to your \litestep\personal folder, and open the popup.rc file with a text editor. That file gets loaded for any theme you might be running. You can find the doc for it here: \LiteStep\modules\docs\popup2-2.1.4. The appearance definitions (first main section) are generally defined by the theme you're running. The popup layout (second main section) is all yours to mess with, defined in that popup.rc file. Just make sure to back it up first!