Washed out colors on Ubuntu 20.04?

I have a seemingly common issue with washed out colors on Ubuntu. I'm using HDMI 2.1 and things were fine until today, and all of the sudden after disconnecting the cable and reconnecting colors appeared washed out.

I found my interface is HDMI-0:

(base) stark@UNBREAKABLE:~$ xrandr
Screen 0: minimum 8 x 8, current 3840 x 1600, maximum 32767 x 32767
DVI-D-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected primary 3840x1600+0+0 (normal left inverted right x axis y axis) 880mm x 367mm
   3840x1600     59.99*+  30.00  
   2560x1440     59.95  
   2560x1080     59.98    59.94  
   1920x1080     60.00    59.94    50.00  
   1600x1200     60.00  
   1280x1024     75.02    60.02  
   1280x800      59.81  
   1280x720      59.94    50.00  
   1152x864      75.00  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       59.94  
   640x480       75.00    59.93    59.94  
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)

Some posts here say this should fix it:

xrandr --output HDMI-0 --set "Broadcast RGB" "Full"

But when I run it, I get this BadName error:

X Error of failed request:  BadName (named color or font does not exist)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  11 (RRQueryOutputProperty)
  Serial number of failed request:  37
  Current serial number in output stream:  37

But in any case, running nvidia-settings shows I should already be with Full color range:

I restarted the machine, but no luck.

What am I missing?