For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:python:binary/openSUSE_Tumbleweed/home:Simmphonie:python:binary.repo
zypper refresh
zypper install DisplayCAL
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:python:binary/15.6/home:Simmphonie:python:binary.repo
zypper refresh
zypper install DisplayCAL
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:python:binary/15.5/home:Simmphonie:python:binary.repo
zypper refresh
zypper install DisplayCAL