A clone of KDE/Plasma 5's "Breeze" window manager theme. It is designed to go well with the Breeze GTK theme offered by dirruk1.
I got lazy and some of the "pressed" states are missing their own assets. Feel free to fork this and add them.
git clone https://github.com/psy-q/xfwm-theme-breeze.git ~/.themes/Breeze-xfwm
You can of course call it whatever you like on your local machine.