iPad is a consumer product. Everything has specs and tolerances, and if a product's specs are within tolerances of millions of people, but outside of
your heightened tolerances... well, frankly, nobody gives a $#|t. If you're at a party and everyone is having a great time and enjoying food and drinks and you come and taste food and think it's terrible... well, just go away, find a different party.
I've looked at dozens of iPads at the stores, and have owned dozens of Apple products over the years, and never seen a yellow screen, and all my purchases have always been impeccable, ZERO (0) returns. I have no doubt, however, that if some OCD like you examined my gadgets, they'd find dozens of yellow screens, millions of missing gamuts, dead pixels, dents, scuffs, dinasaur DNA antimatter, marcian life ad infinum