    def set_theme(self, theme):
        """
        Pick a palette from the list of supported THEMES.

        :param theme: The name of the theme to set.
        """
        if theme in THEMES:
            self._theme = theme
            self.palette = THEMES[theme]
            if self._border_mgr.can_scroll:
                self._border_mgr.scroll_bar.palette = self.palette
Pick a palette from the list of supported THEMES.

:param theme: The name of the theme to set.
asciimatics/widgets/frame.py