To reproduce on a standard ubuntu machine, install "gtk3-engines-oxygen" and set org.gnome.desktop.interface.gtk-theme to "oxygen-gtk" and run e.g. "software-center search:myth".
To reproduce on a standard ubuntu machine, install "gtk3-engines- oxygen" and set org.gnome. desktop. interface. gtk-theme to "oxygen-gtk" and run e.g. "software-center search:myth".