yast2-theme-SLE from YaST:Head project
Select Your Operating System
Add repository and install manually
For openSUSE Leap 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/YaST:Head/openSUSE_Leap_15.4/YaST:Head.repo zypper refresh zypper install yast2-theme-SLE