I bought a retina mini after returning my air because I like it better. The first one was really yellow at the bottom. Like, it looked like a swath of pollution had settled at the bottom half of the screen. I did an exchange, and the second one was a little better, but still predominantly yellow on the bottom. Both serial numbers were different for the first half, meaning that the displays did come from different manufacturers. At this point I was becoming fairly disappointed, because I did not want to get stuck in a return loop, and I had already returned a couple iPad airs, soI was starting to feel guilty about doing it all the same store. I drove to a different Apple Store, and explain the situation but I was looking for an iPad with a great screen. The associate was understanding but because I was honest and had told him that I returned it twice, he replied by saying he would let me do ONE exchange because "it costs the company money". And wrap the new iPad, held my breath, and.... Yellow. Not only was the screen yellow, this one had pretty severe light leaks. I left the store with the crappy iPad feeling pretty disheartened. There's only one more store I could try, about 40 km away. I decided to try it. I went in and just bought a fresh iPad, without returning or exchanging. I opened it up, turned it on and... BINGO. The holy grail, an ipad mini retina with a uniform screen!! I brought the crappy one in from my car and explained the situation, and they took that one back no fuss. I suppose what I am trying to say is that, don't become disheartened, the unicorn screens are out there, and you just need to land the right one. Also, try different stores as hey may get different batches of then in.... This one came from a fairly remote store (the furthest one north in Canada).