Figure 1a below shows the measured Color Gamuts for the Apple iPhone XS Max along with the Standard sRGB / Rec.709 and DCI-P3 Color Gamuts. 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.
Accurate White Points
The dots in the center are the measured color of White for each of the
Color Gamuts along with the D65 Standard White,
which is marked as a white circle.
To deliver accurate image colors the display must match both
the Standard Color Gamut and the Standard Color of White.
Accurate Color Gamuts
The Standard Color Gamuts are marked with Black and Gray dots in
Figure 1a
below.
The iPhone XS Max Wide Color Gamut is an accurate match
to the DCI-P3 Standard Color Gamut
that is used to produce the new 4K UHD TV content.
The smaller Color Gamut is an accurate match
to the sRGB / Rec.709 Standard Color Gamut
that is used for most existing consumer content.
Both of the iPhone XS Max Color Gamuts are a close match to the Standard Gamuts.
See this
Figure
for detailed
Absolute Color Accuracy
measurements for each of the Color Gamuts.
The Reduction in the Color Gamut with Ambient Light
Figure 1a
above shows the Color Gamuts in 0 lux Ambient Light,
which is absolute darkness.
Figure 1b
below shows the reduction in the Color Gamut with increasing Ambient Light.
At 500 lux, which corresponds to typical office lighting, the on-screen Color Gamut is reduced to 94%. At 1,000 lux, which corresponds to very bright indoor lighting or outdoor daylight with an overcast sky, the on-screen Color Gamut has fallen to 85-87%, and at 2,000 lux, which corresponds to typical outdoor daylight in shade, the on-screen Color Gamut has fallen to 72-74%.
