Color on the Retina iPad Mini Link
As always, Anandtech gets into the details where other reviews do not.
The iPad mini with Retina Display has the same color gamut as the standard iPad mini, which is narrower than the iPad Air and less than the sRGB coverage we normally look for. The biggest issue here is that there are other smaller tablets in this price range that do offer sRGB coverage (e.g. Nexus 7, Kindle Fire HDX 8.9).