I don't know if it is possible but I'd suggest to create a package (or packages) for colour presets that could be used with any theme, instead of having different versions of the theme only to differentiate between colours. Now in colour presets I can only see current or default presets for a given theme. I would also move Font colours to a new windows and put a selector for font colour preset (choose between installed ones) and a button to define custom, which would show the controls that are right now integrated in main screen.