Adapta - A Material Design Gtk+ Theme for Ubuntu and Linux Mint

Install Adapta Theme on Ubuntu 16.04 or Linux Mint 18. Open your terminal (Ctrl+Alt+T, Unity Ubuntu)

sudo apt-add-repository ppa:tista/adapta -y
sudo apt-get update
sudo apt-get install winehq-devel

sudo apt update

sudo apt install adapta-gtk-theme

Setting Up Adapta Theme on Ubuntu 16.04. Before using Adapta, you need to install unity tweak tool:

sudo apt install unity-tweak-tool