In the version Pro and XPro In (X) the own Design (Framesite, Design, Cells, Font, Language, additional form fields, etc.) can be made in the templates (HTML Format). Thouse are maintain when the Shop will be new generated.
Here the selected standard templates can be eported into a templates folder.
Menu option: File/Templates export...

The exported templates can now be edited with a HTML editor..
By generating the Shop the used templates folder can be selected now. For each customer an own folder can be selected. Do not export the Shop into the templates folder, otherwise the templates were overwritten!

Reference : If the Shop programm does not find a templates file in the indicated templates folder, then the internal templates becomes automaticly used!
See also: Work with templates