Unable to configure IDLE

I want to customize the appearance of Python 3.7.2 using the OPTIONS>CONFIGURE IDLE>SETTINGS. After making a few changes, I am unable to save them. When I press on APPLY or OK, nothing happens. Could someone give some advice to a newbie like me? I would be grateful.

Whilst I cannot solve your question, I used to use IDLE but have since moved to PyCharm (there is a free version). Makes you maintain your code and learn good habits much easier, has error checking and made my Python programming less painful.

Would really recommend you check it out.