I've installed notepad++ with wine. If I run this application it looks like Win95.
So now twenty years have past and I would appreciate a look that is a tiny bit more state of the art.
I found this solution: https://askubuntu.com/a/219795/249909
Applying the accepted answer results in nicely looking winecfg. But notepad++ still looks ugly as before.
Not only that: Using the theme causes that the toolbar of notepad++ is not longer visible:
So, instead one step forward this was one step back. How to solve this?