Kivy -如何在满足条件时更改每个文本输入的颜色

from kivy.app import App
from kivy.uix.textinput import TextInput
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder

class CustomTextInput(TextInput):
    def __init__(self, **kwargs):
        super(CustomTextInput, self).__init__(**kwargs)
        
        # 在此处添加满足条件时的颜色更改逻辑
        if 满足条件:
            self.background_color = (1, 0, 0, 1)  # 设置背景颜色为红色
        else:
            self.background_color = (1, 1, 1, 1)  # 设置背景颜色为白色

Builder.load_string('''
<CustomBoxLayout>:
    orientation: 'vertical'
    CustomTextInput:
        id: text_input1
    CustomTextInput:
        id: text_input2
''')

class CustomBoxLayout(BoxLayout):
    pass

class MyApp(App):
    def build(self):
        return CustomBoxLayout()

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