FinalStep allows you to specify a background for all your windows, which could be fixed or specified by the user. You may choose between a graphic wallpaper, a plain color background (specially useful for slow computers or remote access) or just nothing.
The option "Background" in the "Window Background" group allows you to define how your program will behave. The options are "Wallpaper", to specify a graphic as a wallpaper, "Plain color", to specify a selected background color, or "both" so the user may choose what he wants.
If you don't want to use either option, you may activate the option "Don't generate code", found below.