Please, enable dithering by default dor eDP panels (18 bits) such as was done for LVDS panels.
The code in nouveau git will now attempt to automatically determine whether it should enable dithering or not for a given display, so this should be resolved.
Please re-open if it doesn't work for you, with your dmesg output and the output of /sys/class/drm/card0-eDP-1/edid attached.
Created attachment 53385 [details]
EDID file for eDP-1
Not sure if F16 sports this patch so I'm attaching the EDIT file just in case.
This comes from a Dell XPS l702x.