Apple iPad mini: S-IPS Subpixels
The iPad mini and iPad 2 both offer 1024x768 resolutions. However, the mini's screen is naturally smaller, which means its pixels are packed more tightly together. In fact, we know that the iPad Mini's LCD sports 163 pixels per inch (PPI), while the iPad 2 fits 132 PPI. As mentioned, both of those numbers are too low to qualify for Retina Display branding.
Rendering 48% of the AdobeRGB 1998 and 69% of the sRGB gamut, the iPad mini's color saturation is the same as the iPad 2.
If you map out the gamuts in 2D, the iPad mini basically overlaps the iPad 2. We're not necessarily bothered that Apple's display quality isn't any better on the mini than it was almost two years ago. The issue is that Apple's competition stepped up its game. The Nexus 7 and Kindle Fire HD both deliver more color saturation, the former by just 2%, but the latter by 11.
Two percent doesn't sound like much, but don't underestimate Google's Nexus.
In the video above, we've modeled the Nexus 7's (wire-frame) and iPad mini's (solid) gamuts in the Lab color space. It works like this: the top colors are highlights, or bright hues. As you go move down the vertical axis, the colors get darker. The gamut volume represents all the colors that a device can render.
We see that the iPad mini is able to render brighter reds, magentas, and a wider range of greens and cyans. The Nexus 7 sacrifices some range in green and yellow for brighter hues. The real difference is in the dark blue and magenta region. The Nexus 7 simply displays a huge range of hues that the iPad mini cannot.
Interestingly, the iPad mini reaches a somewhat higher brightness than the iPad 2, but suffers from slightly poorer contrast, since it struggles to render a true black. Yet, we can applaud Apple for getting color temperature much closer to the 6500 K standard. Gamma is still a bit high, but it's not terrible at 2.42.
Amazon's Kindle Fire HD comes across amazingly well. It scores a really high gamut volume and comes close to the professionally-calibrated 6500 K and a 2.2 gamma standards.