How to turn off current display profile for Displaycal calibration/profiling?

Software
1

I’ve just noticed that Displaycal doesn’t seem to be able to turn off colour management for my display when measuring patches for new profiles.
If I pause the process and go into GNOME settings > Colour Management I can change display profiles and see the test patch in Displaycal changing colour. Toggling off the graphical switch for the display doesn’t seem to do anything either: selected profiles are still getting applied, even with the switch off.

Am I missing something?

Debian 13, GNOME 43, Wayland (same behaviour in Xorg session though).

colour-management
colour-management1920×1200 1020 KB

2

This also seems to be the case whether I install from the Debian repo or as a flatpak.

3

I don’t think that running displaycal in a wayland session actually works. The protocols aren’t there to actually do anything.

4

It depends what you mean by ‘do anything’. It can display and read patches and make profiles, but it can’t set or ‘install’ them. I can manually set display profiles in my system settings though, so that’s not a big deal.
The problem is that it can’t disable colour management for the display in order to do its work on a ‘clean slate’. And neither can GNOME Settings seemingly…
I need to find another way to do that. Otherwise Displaycal is always reading patches through a pre-existing display profile.