To add the repository and install, open the Terminal and run:

sudo dnf config-manager --add-repo https://download.opensuse.org/repositories/hardware:/razer/Fedora_$(rpm -E %fedora)/hardware:razer.repo
sudo dnf install polychromatic

Fedora Rawhide users, use this instead:

sudo dnf config-manager --add-repo https://download.opensuse.org/repositories/hardware:/razer/Fedora_Rawhide/hardware:razer.repo
sudo dnf install polychromatic

For binary packages, visit the openSUSE Build Service.

Next up, OpenRazer

Polychromatic is just a frontend. If you haven't already, you'll need to install this driver and daemon: