Similar questions have been asked before but so far they have not solved this problem.
On my laptop (Dell Precision 5510 with hybrid graphics GPUs Intel/Nvidia) with Ubuntu 16.04 the colors are washed out when connected to external display with HDMI. This does not happen on Windows or on the laptop screen. My guess is that this is related to limited RGB color settings (16:235 instead of 0:255).
I have tried
xrandr --output HDMI-1-1 --set "Broadcast RGB" "Full" but it did not help.
I did not find any related settings from NVIDIA X Server Settings (
NVIDIA Driver Version: 381.22