For color profiles management you may want to try colord-kde (sudo apt install colord-kde, tested on KDE Neon/Ubuntu 18.04)
Too bad Wacom & Co don't support Wayland at all, Plasma Wayland is so smooth that makes X11 session looks from '90 😔
@post Tested? Is it sincerly working on your side? Because my test on 18.04, Neon to 20.04 returns it fails at calibrating and more (and that over two machines). The GUI appears, the function behind it fails. ( Most fresh report: https://bugs.kde.org/show_bug.cgi?id=417157 )
@davidrevoy tested in applying the ICC profile sorry
@post Ha, thanks for the feedback. Yes, this part seems to work with conditions. (I have to investigate; it would be easy to blame nvidia-driver; multi-display as the feedback on the bug-report so far have this in common). Can you tell about your setup?
Some years ago I was involved in the rewrite of the GUI (an entrepreneur paid a KDE dev to work on the whole stack) and at the time everything worked well. Now I can't test the calibration.
About my setup I have a Lenovo Yoga 720 13'' with integrated Wacom tablet and an Intel 620 GPU.
In my experience Nvidia can be really really problematic so I only use Intel now...
Anyway thanks for your efforts in improving the situation on Linux/Plasma
