Found that Adaptive Picture defaults to ‘on’
been going around trying to find out what was wrong… True Tone, tinting, timing, warming, eye saver, or adaptive picture
it was the last one - maybe this will help someone - got a 37” D80 monitor and it kept color shifting to warm - then back to normal
do you remember when I was getting into hex colors and posting the ultimate ‘cream’ set? 
lol 
all were different because of adaptive color…. I kept changing the results BECAUSE the monitor changed color—- hahahaha can laugh 
now - at the time thought it was eye strain - or too much screen time - or I couldn’t discern colors well…
if it happens to you - check your settings!!