I ran into the same problem myself recently. OpenSuse 15.2 still has DisplayCAL in their repositories, Tumbleweed dropped Python 2.7, so no DisplayCAL available on the rolling system.
What helped me, was this article using cli to calibrate/profile the monitor.
As I am just a user without deeper knowledge here, at least I can say, that I ended up with a display-profile, that seems reasonable (selecting it on and off shows sane color changes) and works under Plasma (single display setup).
I was wondering, if an appimage could be of a help here. If Python 2.7 gets statically build into the package, shouldn’t it become independent of the distributions sources? Would that be a workable hack until python 3 is implemented? Besides the technicalities, are there security concerns thinking that way?