RT and GNOME 40 color management problem? (on Debian testing/bookworm)

I am on Debian testing/Bookworm and I got updated to GNOME 40.

In editor main window there is a monitor profile selector (lower border of editor window), with a selection of icc profiles and System Default (from GDK), if a default exists.

If I compare “System Default (from GDK)” with “None”, I get the same color output with GNOME 40. In GNOME 38 there was an obvious difference.

If I compare “System default (from GDK)” with “my EIZO monitor profile from calibration” I now see a difference in GNOME 40. In GNOME 38 they were the same. “System default (from GDK)” is my normal setting.

I have selected my “my EIZO monitor profile from calibration” profile in GNOME color management setting, so GNOME is aware of the icc-profile for the monitor.

I have a wide gamut EIZO monitor which I calibrate regularly. Debian 11 Bullseye GNOME 38 was fine. For GNOME 38 “System default (from GDK)” = “my EIZO monitor profile from calibration” (same rendering) in RT editor window and “none” was an obvious un-calibrated state.

Is it so that Debian testing/Bookworm and GNOME 40 is not compatible with RT-git-dev (from source) and RT-5.8 from Debian package? I have tested both and I get the same issue.
EDIT: Debian testing/Bookworm GNOME packages are not all of the same version. But GNOME system info now displays GNOME 40.x. Has anyone else seen this issue of color management/rendering?

I am uncertain as to what has happened. I have been fine for a year on Debian Testing Bullseye + RT-git (from surce) and suddenly it changed when GNOME was updated to GNOME 40.

I wish I could describe the color rendering error in more objective terms.

Are you sure you haven’t found your way into a Wayland session?

@paperdigits Good point. I will double check when I get back.

At least I was on X whilst on Debian Bullseye because of 30 bit depth and nonfree Nvidia. I am not aware that this has changed when doing dist-upgrade to Debian Bookworm.


If you’re willing to install darktable, you can run darktable-cmstest in the terminal and it’ll give you a report on your color mgmt config

@paperdigits, thank you. Good to know. I will use this if problems persist. I might also analyze my next Debian install.

I suspect, but I do not know, the halfway installation of GNOME 40.4.0. Problems started when GNOME Version showed 40.4.0 and the desktop layout changed. This is will be resolved (in weeks?) as Debian testing stabilize on GNOME 40. => Waiting is one option. Edit: status: Status of GNOME 40 in Debian

However, I think I will just reinstall Debian 11 Bullseye stable.

The counterexample is if someone else is running Debian Bookworm, latest update, and everything is fine.

Back on Debian 11 Bullseye stable and all is well on GNOME 3.38.5 with RawTherapee-git, from source.

I will let Debian 12 Bookworm testing stabilize, when it comes to GNOME.

I still have no idea what happened. My only hypothesis is that GNOME 40 on Debian testing is not entirely mature and ready. Maybe it will stabilize soon.

I used Debian 12 Bookworm testing to compile latest GIMP git source, for GIMP 2.99.x. At least one library is only available in Debian testing. I can install that library separately or check out an older commit of GIMP git.