code: def set_theme(self, theme_name, toplevel=None, themebg=None):
          
          if self._toplevel is not None and toplevel is None:
              toplevel = self._toplevel
          if self._themebg is not None and themebg is None:
              themebg = self._themebg
          ThemedWidget.set_theme(self, theme_name)
          color = self._get_bg_color()
          if themebg is True:
              self.config(background=color)
          if toplevel is True:
              self._setup_toplevel_hook(color)
docs: Redirect the set_theme call to also set Tk background color