def show_popup(): show = P() # Create a new instance of the P class clr_picker = ColorPicker() clr_picker.pos_hint = {"x": 0.05, "top": 0.99} show.add_widget(clr_picker) def on_color(instance, value): print("RGBA = ", str(value)) # or instance.color global mcolor res = tuple(value) mcolor = list(map(mul, res, (255, 255, 255, 255))) temp = 0 temp = mcolor[0] mcolor[0] = mcolor[2] mcolor[2] = temp mcolor = tuple(mcolor) print(mcolor) clr_picker.bind(color=on_color) popupWindow = Popup(title="Popup Window", content=show, size_hint=(None, None), size=(600, 600)) # Create the popup window popupWindow.open() # show the popup