buttons_example.py

from kivy.app import App
from kivy.lang import Builder

KV = """

<Widget>:
    background_color: (1,1,1,1)
    background_normal: ""
    color: (1,0,0,1)
    font_size: "30sp"

BoxLayout:
    Button:
        text: "Button1"
    Button:
        background_color: (0,0,0,1)
        color: (1,1,1,1)
        text: "Button2"
    Button:
        text: "Button3"

"""

class MyApp(App):

    def build(self):
        return Builder.load_string(KV)


MyApp().run()