I am not sure if I am doing it wrong but when I want to swap/replace colours of an imported image the swap/replace does the job but the 'Edit/Undo - Redo' menu is greyed and the Ctrl-z command does not work. Is this my doing or is it the software's feature?
(I got KXStitch installed on Ubuntu/GNOME).
This is by design. The undo redo was intended to reverse destructive edits in the main editor. The palette changes are fairly simple to reverse and I didn't include undo for this.