如何在Kivy中更改TabbedPanelItem的背景色

from kivy.app import App
from kivy.uix.tabbedpanel import TabbedPanelItem
from kivy.lang import Builder

TabbedPanelItem:
    background_color: 0, 1, 0, 1  # 设置TabbedPanelItem的背景色为绿色

class MyTabbedPanelItem(TabbedPanelItem):
    pass

class MyApp(App):
    def build(self):
        return Builder.load_file('main.kv')

if __name__ == '__main__':
    MyApp().run()