Figure 1 shows the measured Color Gamuts for the iPad iPad Pro 9.7 together with the traditional sRGB / Rec.709 Color Gamut in black and the newer Wide DCI-P3 Color Gamut in Yellow. 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.
The dots in the center are the measured color of White for the iPad Pro 9.7 along with the D65 Standard White, which is marked as a white circle. To deliver accurate image colors the display must match the same Color Gamut and Color of White that was used to create the content.
Both of the measured Color Gamuts for the Pad Pro 9.7 are almost exactly on top of the standard sRGB / Rec.709 and DCI-P3 Gamuts, so they are mostly obscured in the figure.