Why are you here Dino you think you are helping and by the way I am using my iPhone to post. Dude you got away with a free upgrade man why are you here, that's my question. Had 2 iMac 21 inch, upgraded by a apple rep who told you yes, when you requested a 27 inch model and you have a ilemon like all of us so call have. Sabotage haahahah, I gotta laugh, you know 99.9 percent of the screen I have seen here are perfect. Why test your screen with the grey bar when you don't see the iLemon, I say this again and probably all the time if you don't see it with normal use of the screen, then it's fine of coarse there is variability with the grey bars.
But stop beating on the dead horse man, you got an iMac for half what it cost. Let me save your trouble and many others, apple is not going to solve this for you or any new iMac why because this is something that is not part of apple, apple is not going to tell LG. I'm not going to put any more of your panels until the iLemon is over.
Stop beating on the dead cattle it's not going to happen be happy with your 21 inch oh wait 27 inch that has a price tag of a 21 inch. For the rest you see the iLemon get a refund or that MacBook pro with LG all over it also. I have a MacBook 13 inch alum and a MacBook pro 17 both also have slight ting if you all feel happy. Also my iMac has a yellow ting also. Sorry that my big mac doesn't. Look like the one on the photo, I should return all big macs because it is not advertise as in the photo.