I revived my machine with Windows and tested a few themes from gnome-look today and most of them weren't very usable. The win32 theme is just too buggy to be used. So I tried to further improve the modified prof-gnome theme at
https://github.com/geany/geany-osx/tree/master/Prof-Gnome/gtk-3.0
to improve how it looks on Windows (and Mac too). If interested, I'd suggested to give it a try. On Windows, I'd suggest to make the following changes: 1. In `theme-colors/colors-light.css` change `text_color` at the beginning of the file to `#000` for higher contrast (on macOS it looks a bit too dark so I didn't change this in the repo). 2. In `settings.ini`, add `gtk-toolbar-icon-size=GTK_ICON_SIZE_SMALL_TOOLBAR` (the small icons just look better)