The Retina iPad mini promises all the pixels of the iPad Air at the density of the iPhone 5s. That's 2048x1536 at 326ppi. If that sounds like a screen-dream come true, in many ways it is. Unfortunately, the Retina iPad mini only provides the same, narrower color gamut of the original iPad mini. That translates into reds that appear slightly less saturated on the Retina iPad mini than they do on any of the full-sized Retina iPads, or Retina iPhones. Anand Lal Shimpi ran his usual, comprehensive battery of tests for AnandTech:
I suspect the justification here is Apple likely views the bigger iPad as being a better fit for photographers/those who care about color reproduction, but it's a shame that this is a tradeoff that exists between the two iPads especially given how good Apple is about sRGB coverage in nearly all of its other displays.
It's most apparent when you put a Retina iPad mini beside an iPad Air.
For most people, especially people only using an iPad mini, it will likely pose no problem whatsoever. Those with both a full sized Retina iPad, as well as photographers, digital painters, and those with especially keen color sense, might want to take a careful look before taking a purchase plunge.
Personally, and I say this as someone with a design background, I forget about it after using the Retina iPad mini for while (the human brain is remarkable at environmental correction). However, it's disappointing to say the least that Apple hasn't pushed the same panel quality down to the iPad mini line yet. Hopefully the economics and positioning work our better next time.
There have also been some reports of image retention on the iPad mini with Retina display, similar to what plagued the 2012 Retina MacBook Pro. I've tried Marco Arment's test on multiple units now, and haven't experienced it. Often, however, it depends on the panel supplier and even batch, so if you do have the problem, don't hesitate to take it back to Apple as soon as possible and swap it for one that's not affected (run the test in the store!).
If you're contemplating a Retina iPad mini, how much, if at all, does color gamut matter to you? If you have a Retina iPad mini, are you noticing either the color gamut or image retention?