As you are no doubt aware tkinter introduced a theme (or tile) based module. Searching the web I was struck by how little the new capabilities were demonstrated, questions and answers concentrated mostly on how to colour widgets and suchlike.
A quick tour, with working examples, through the tkinter.ttk Style module, so that you should be able to test a widget and check its styling changes on your own ideas and scripts.
An even more lightning tour through the themes from tkinter.ttk and ttkthemes.
Create a few specials to show what can be achieved then create a standalone version, after that you are only limited by your imagination, where an appreciation of PIL (Pillow) will be useful.