Changes the value of palette in dconf

def on_palette_name_changed(self, combo):
        """Changes the value of palette in dconf
        """
        palette_name = combo.get_active_text()
        if palette_name not in PALETTES:
            return
        self.settings.styleFont.set_string('palette', PALETTES[palette_name])
        self.settings.styleFont.set_string('palette-name', palette_name)
        self.set_palette_colors(PALETTES[palette_name])
        self.update_demo_palette(PALETTES[palette_name])