Display P3

What it is

Display P3 combines the primaries of the DCI-P3 cinema standard with the D65 white point and the sRGB transfer curve. The result is a space with the same tonal behaviour as sRGB but noticeably more saturated red and green primaries, covering roughly a quarter more of the visible spectrum.

Apple adopted it across its displays and cameras, and many recent monitors, phones and laptops from other manufacturers now cover most or all of it. In practice a large fraction of photographs taken in the last several years are captured and stored in Display P3.

What it looks like when it goes wrong

A Display P3 image with its profile stripped is interpreted as sRGB. The numbers are unchanged, but they now mean less saturated colours, so the image renders flat and slightly shifted — most visibly in reds, which lose their intensity.

The opposite error is rarer but uglier: an sRGB image assigned a P3 profile renders oversaturated, with skin tones going ruddy.

Both come from the same confusion between assigning a profile and converting to one. Converting preserves appearance by changing the numbers; assigning changes appearance by changing the interpretation.

Shipping it safely

Browsers have handled tagged wide-gamut images correctly for years, so the safe approach is to keep the P3 data and keep the profile attached. A colour-managed browser on a wide-gamut screen shows the extra saturation, and on an sRGB screen it converts down.

The unsafe approach is stripping the profile to save a few kilobytes. That is the one action guaranteed to produce wrong colours, and it is what a careless metadata-stripping step does.

If your pipeline cannot be trusted to carry profiles, convert to sRGB deliberately at export instead. Slightly reduced saturation everywhere is a much better outcome than wrong colours on the devices most likely to be looking.