I am presently using the 3rd replacement device that I have received since my original purchase. I have come to the conclusion (which several of other members on this forum have already stated) that all Surface displays have at lease some subtle variances in color/contrast from one side of the screen to the other. The yellow band has been visible on every unit I have received, and is certainly present on the display models I have seen at Best Buy.
You can ask for a replacement unit, but there is no guarantee that a new device will not have the same or similar display problems.
I have gotten used to the way my SP3 looks, and I don't dwell on the flaws. In every other way this is the absolute best computing device I have ever owned.
Would I like it to be perfect? Of course, but that might have to wait until SP4...