SciTE Customization GUI is intended to be your one-stop solution for your SciTE customization needs. With SciTE Customization GUI you can create new themes from scratch without having to touch a single configuration file.  Simply select 'Default Theme' from the file menu.  This will start you out with a default theme.  Then make your changes to the theme.  Finally, select 'Save As' from the file menu and give it a name.  Or you can select from an already existing theme. You can see liv