Question on seemingly new color profile calibration on Dell XPS Adobe RGB Laptop

[Frank M]

Hello! I'm Frank M & new here, and hoping this fits the etiquette of this
list.

I noticed after doing a from-scratch install of Ubuntu 22.04 on my Dell XPS
15 9550 with the Adobe RGB 4K display, Ubuntu seems to be using a better
variant of color correction than in the past. Where is the source code for
the hardware interface for that kind of thing? Tried in xorg / colord /
gnome-system-settings, didn't find anything Dell specific (at a first
glance using Ctrl-F)

===== Overly Verbose Background info =====

I've done a lot of tests with this on both Windows, Linux (and macOS
surprisingly). Found that macOS gets it completely right: Wide gamut can be
seen, but nothing appears incorrect (directly taking an sRGB color by the
RGB triplet, and rendering the resulting color in the display's native
space).

Windows does things the ugly way (aka unmanaged). If I put the Dell
recommended profile into color settings, most color aware apps get the
hint, and start acting like macOS. There's also an OEM app that somehow has
hooks into the graphics system to tell the display itself to switch to an
sRGB mode, so as far as Windows is concerned the display is native (ish)
sRGB. This mode unfortunately causes visible banding at the hardware level
- Windows screenshots do not see that.

Ubuntu 21.10 and before always acted like an unmanaged Windows: Colors
would be punchy & overblown, but if I used Xorg and not Wayland, Firefox
(after fixing the gfx color about:config setting) & Chrome would use the
EDID-discovered profile, and correctly convert from original color space to
the Dell native one before rendering. This allowed for seeing wide gamut
colors.

Now - in 22.04, if I use the EDID-discovered ICC profile, it seems the
entire desktop is assumed to be sRGB, mapped to the Display native profile,
then rendered (meaning colors appear less punchy and correct, but now the
system is running in sRGB mode). I can turn this off by choosing an sRGB
profile in gnome-system-settings, but then everything thinks I'm using an
sRGB profile rather than native, and I get punchy colors again.

Is it possible to switch back to the previous way colors were converted?

Thanks if you've made it this far!
Frank M
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