@elextr, there is no default GTK theme on Windows, and no automatic updates, of course. I found this theme: https://github.com/vinceliuice/stylish-gtk-theme , copied it in **C:\Users%USERNAME%\AppData\Local\gtk-3.0** , chosen one of the variants (Dark Jade) and tweaked it to make Geany look nice (to my taste :). Also I edited some lines in **geany.css**, but it's very little part of the style.