Hi my name is oren and i am from israel and i find amazing solution for the problem of yellow screen in iphone x.
the solution is to make a yellow wash to the screen.
open true tone and night shift and put it on the high warm. put the brightness on high.
leave the iphone like that about half an hour preferably with a white background.
after that close true tone and night shift and look the screen and you love what you see. a nice white screen with no yellow at all.
do it again after a while and the yellowish disappear forever.
Anybody else has tried this weird method?