Install gtk2-engines-murrine by entering the following commands in the terminal:
sudo apt update sudo apt install gtk2-engines-murrine
Description:
cairo-based gtk+-2.0 theme engine
"Murrine" is an Italian word meaning the glass artworks done by Venicians glass blowers. The Engine is cairo-based, and it's very fast compared to clearlooks-cairo and ubuntulooks. . This package includes the Murrine engine.
Version: 0.98.2-2ubuntu1
Section: x11