I am making a calculator program and don't want the user to type directly into the Entry,
so I made the Entry 'readonly'. But that makes it to dark for my liking, so I am trying
to set the readonlybackground='white', but it gives me an error saying that it doesn't
recognize 'readonlybackground'. I am using Python 18.104.22.168, I don't know if that is the reason.