Arc is a flat GTK theme with transparent elements for GTK 3, GTK 2 and Gnome-Shell. It is available in 3 variant Arc, Arc-Darker,Arc-dark. It supports GTK 3 and GTK 2 based desktop environments like Gnome, Unity, Budgie, Pantheon, XFCE, Mate, etc.
Install Arc GTK Theme on Ubuntu Linux
Arc theme is available via the default Ubuntu repositories. You can easily install it via terminal command line application. Open terminal app via ctrl+alt+t keys or via application menu and run below commands one by one.
sudo apt update
sudo apt install arc-theme
To apply the theme use GNOME Tweak Tool or Tweaks. You can install Tweaks tool from the below link.
How to install Unity Tweak Tool on Ubuntu Linux
After the installation open the Tweaks from application menu or via below command.
gnome-tweaks
After that click Appearance from the side menu and select the Arc theme from the Themes Applications options . That’s it.
To know more about this visit the arc theme homepage.
Arc Theme Samples: