def build(self):
# use a (r, g, b, a) tuple
btn = Button(text ="Push Me !",
font_size ="20sp",
background_color =(1, 4, 6, 1),
color =(1, 1, 1, 1),
size =(32, 32),
size_hint =(.2, .2),
pos =(300, 250),
# Disabling the button
disabled = True
)