List tools to inspect color management in X11/Wayland

I've recently started messing with how Linux handles color management and this repository is great to consolidate information, nice job!

One thing I've been missing during my research is a consistent list of tools with which I could inspect, compare and change different parts of the display system in X11/Wayland.

I can consolidate that into a proper page if you want, but here are the ones I've collected so far:

List information communicated by the display via EDID (using edid-decode):

edid-decode < /sys/class/drm/card0-eDP-1/edid

List information communicated by the display via DDC (using ddcutil ; not all displays support this, mine doesn't):

ddcutil capabilities

Dump all information colord is aware of, including a list of profiles stored on the system:

colormgr dump

Dump what XrandR knows about all outputs, which includes a lot of information about curves/color:

xrandr --query --verbose

Dump the current VCGT Intensity + RGB tables for display #1 (using ArgyllCMS):

dispwin -d1 -s current_vcgt.cal

Display/change the current X11 "gamma" setting (not sure where that is in comparison with VCGT, it does not seem to change it according to dispwin above):

xgamma
xgamma -gamma x.y

Display/change the XrandR "gamma" setting (what do you know, this one does change the VCGT, but only RGB components, not the intensity!):

xrandr --output eDP1 --gamma x.y

Not sure about this one, but I think this tags the HDMI output so that the monitor can adapt its own factory calibration to a given colorspace (completely ignored on my display, but I know some high-end displays have specific calibrations that understand that the incoming HDMI/SDI signals are in, say, Rec.2020 PQ):

xrandr --output eDP1 --set Colorspace BT2020_RGB

Dump internal state known by DRM (using proptest from libdrm):

proptest