However, I had written the code in Python, so I had to make a choice. The Tkinter toolkit lets you ... and background colors. A ttk button uses a style system that is more complex to set up ...

Code below has 1 major and 1 minor problem. Major issue is, once you push the button it visually stays pushed. Minor problem is, I run this in Cygwin. I've got an rxvt window behind the Tk window.