I got my 5th (and final) PW today. Not bad, but still color hues. However, on this PW, one LED light was quite a bit brighter than the other three, creating a "spotlight" effect. It's going back and I'm keeping the best one out of the 5. I was also given a $30 Amazon credit. The person I spoke to this time was very knowledgeable about the color hues. He said, and I quote "They all have color hues to some degree because one of the screen layers (I think he clarified later that it was the capacitive touchscreen, but I'm not positive) is not dispersing the light the way it should."
He went on to say that Amazon was very well aware of the problem and were working on it, but it would not be a quick fix. He further mentioned that although they all have color hues (predominantly pink), not everyone notices them because the intensity varies from device to device, and also because some people aren't as sensitive to color variations.
I'm not too upset because the screen on the one I'm keeping is pretty good and I'm adjusting to the very faint hues (sometimes I notice and sometimes I don't). I was also very happy to speak to an Amazon rep who knew exactly what I was talking about and discussed the issue at length with me.