As usual, I want to apply my favorite Arc Flatabulous theme into my testing distro. And now, I want to install Arc Flatabulous Theme on my Zorin OS 12. For me, Arc Flatabulous is the best GTK+ theme available.
If you like, you can also download and install Arc Flatabulous theme on Zorin OS with the following commands
sudo apt-get update
sudo apt-get install autoconf autogen libgtk-3-dev git
git clone https://github.com/andreisergiu98/arc-flatabulous-theme && cd arc-flatabulous-theme
sudo make install
Once installed you can open Zorin Appearance and select Arc Flatabulous