Modified and adaptive Paper icon theme for KDE distros.
cd /tmp
git clone https://github.com/varlesh/papirus-icon-theme.git
sudo cp -R /tmp/papirus-icon-theme/papiru* /usr/share/icons/
Also you can install additional icons for some applications (Krusader, Amarok, tray applications). Please , explore directory /usr/share/icons/papirus/extra-icons