gnome-shell-extension-user-theme from home:mantarimay:GNOME project
Select Your Operating System
Add repository and install manually
For standard run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mantarimay:GNOME/standard/home:mantarimay:GNOME.repo zypper refresh zypper install gnome-shell-extension-user-theme