To add theme support for lxlauncher, I think a simple index.theme file structure should works. It can be like this:
Comment=A new theme for LxLauncher
Different pages of lxlauncher can have different backgrounds, so it has a [Default] section, or they can use just color as background without image, if "Background" is like "#00FF00", then "Color" in that section maybe useless.
Is this enough?
I noticed that the code used to load image files with gdk_pixbuf_new_from_file() is commented. Currently it does not support background?