This is a customized version of the Chicago95 GTK theme. This is a theme that I've modified for my own purposes and sharing to you. I don't intend to maintain it indefinitely.
GTK+ 3.18.9
Xfce 4.12
gtk3-nocsd (See INSTALL.md for setup)
(Preferred distro is Xubuntu 16.04 LTS)
Some GTK applications such as Firefox might display inconsistencies such as adopting choice elements of the system theme but attempt to fit them in a flat / material design approach in self drawn interfaces. In regards to visual consistency, this theme may not be perfectly compatible with modern GTK applications.
Libre Office GTK3 doesn't look very good on this theme. I'm not sure why, but I'm trying to fix it. In the mean time you can remove the libreoffice-gtk3 package which will cause Libre Office to fallback onto GTK2 which is far more consistent and looks better.
Click here for install steps.
The reasoning behind disabling Client Side Decorations and fallingback to Server Side Decorations for this theme
I wanted the theme to be usable across both compositing and non-compositing environments. I'm currently unsure of how to make GTK3 applications that are utilizing CSDs to properly render a border in the skeuomorphic style of this theme across both compositing and non-compositing environments.
Grassmunk 4/2016
AdrianoML 12/2016
EMH-Mark-I 4/2017
License: GPL-3.0+/MIT