P3 Color Gamuts
P3 names a family of color spaces that share wide-gamut primaries but can differ in white point and transfer function.
The name P3 turns up on cinema standards, photographs, mastering reports, and television specifications. Resolve the context before treating those uses as the same color encoding:
| Name or use | Primaries | White/transfer information |
|---|---|---|
| Cinema DCI-P3 | P3 | Cinema white point and 2.6 display gamma |
| P3-D65 | P3 | D65 white; specify the transfer characteristic separately |
| Display P3 | P3 | D65 white with the sRGB transfer curve |
| “P3 coverage” on a screen | A measured capability relative to P3 | Depends on the stated measurement method |
All three named spaces use the same primary coordinates: red (0.680, 0.320), green (0.265, 0.690), and blue (0.150, 0.060) in CIE 1931 xy. P3 reaches farther than BT.709 toward saturated red and green. The coordinates determine the gamut; the white and transfer choices complete the interpretation.
Two uses that are easy to confuse
An image in Display P3. Its RGB values use P3 primaries, D65 white, and the defined nonlinear transfer curve. A color-managed image viewer can convert those values to the destination screen while preserving their intended colors. Display P3 provides a wider gamut than sRGB without, by itself, defining a PQ HDR presentation.
A movie graded within P3 and delivered using BT.2020. The movie can fit within the grading display's P3 capabilities while its encoded video uses BT.2020 coordinate values. The conversion expresses the same intended colors as mixtures of different primaries. The player's input interpretation follows the delivered video fields.
In the second case, choosing a P3 input mode merely because the film was graded on a P3-capable display would assign the wrong meaning to the delivered numbers. The mastering range and encoding space have separate places in the production chain.
Use a coverage claim for the question it answers
A percentage of P3 describes a screen's measured reach relative to a reference gamut under particular conditions. Different area or volume methods can give different numbers, so compare measurements that state the same reference and method.
For an Emby video, record the signal's primaries and transfer characteristic independently of the display's P3 coverage. The signal tells the renderer what colors were requested; measured capability tells it what can be reproduced. For bright colored highlights, color volume extends that second question across light levels.