How to change Push Button color in guizero python library

Question

Spy Name Generator Code (guizero python module/macOS) This code doesn't change background color of the push button

# Widgets ---------------
title = Text(app, "Push the red button to find out your spy name")
button = PushButton(app, choose_name, text="Tell me!")
button.bg = "red"
button.text_size = 30`

Want to change the push button's color