code: def edit_scheme(self):
          
          dlg = self.scheme_editor_dialog
          dlg.set_scheme(self.current_scheme)
  
          if dlg.exec_():
              # Update temp scheme to reflect instant edits on the preview
              temporal_color_scheme = dlg.get_edited_color_scheme()
              for key in temporal_color_scheme:
                  option = "temp/{0}".format(key)
                  value = temporal_color_scheme[key]
                  self.set_option(option, value)
              self.update_preview(scheme_name='temp')
docs: Edit current scheme.