yast2-theme-breeze from YaST:SLE-15:SP7 project
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Add repository and install manually
For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/YaST:SLE-15:SP7/openSUSE_Leap_15.6/YaST:SLE-15:SP7.repo zypper refresh zypper install yast2-theme-breeze