Figure 1 shows the measured Color Gamut for the iPad mini 4 Air 2 and Pro along with the Standard sRGB / Rec.709 Color Gamut in black. The outermost white curve is the limits of human color vision - the horseshoe is the pure spectral colors and the diagonal is the Line of Purples. A given display can only reproduce the colors that lie inside of the triangle formed by its primary colors. Highly saturated colors seldom occur in nature so the colors that are outside of the Standard Gamut are seldom needed and are unlikely to be noticed or missed in the overwhelming majority of real images. Note that consumer content does not include colors outside of the Standard Gamut, so a display with a wider Color Gamut cannot show colors that aren't in the original and will only produce inaccurate exaggerated on-screen colors.
The dots in the center are the measured color of White for the iPad mini 4 Air 2 and Pro along with the D65 Standard White, which is marked as a white circle. To deliver accurate image colors for standard consumer photo, video, internet, computer, and HDTV content the display must match the Standard Color Gamut and the Standard Color of White.
The iPad mini 4 Color Gamut is almost exactly on top of the sRGB / Rec.709 Standard and overlaps its black triangle. The White Point for the iPad mini 4 matches and is covered by the iPad Pro White Point.