Metameric Failure and wide gamut color spaces/displays

[Myndex]

Just a brief note with some recent references, regarding an emerging accessibility concern for newer, wide gamut display technology.

Red Primary

sRGB is perhaps the ideal display colorspace for accessible purposes, as the "red" primary color is partially within the visible range for protanopia. Someone with protanopia sees the red primary about 50% darker, but they still may see it somewhat.

This is not true of some of the wider gamut displays, especially Rec2020/2100, aka UHD.

With Display P3, the red primary is expected to be darker than the sRGB red, we have a study planned to examine this with protanopia test subjects.

With UHD/Rec2020, we expect the red primary to be nearly invisible—but this depends somewhat on the bandwidth of the primary.

Metameric Failure

Metamerism, as it relates to display technology, is an open research question. It was discovered that using very narrow-band (laser) primaries, which in theory improved gamut size and therefore color fidelity, resulted in the discovery that individual variations in color perception are more prevalent than expected.

Common color primaries in sRGB for instance, are wide-band, and as a result mask many individual variations in color perception.

Individual color perception shifts as we age, and of course CVD has specific color deficits, which can be helped with wider-band primaries, but narrow-band primaries appear to exacerbate these color vision anomalies.

Recent References

Metamerism Experts’ Day Debrief - Industry experts gather about the topic of metamerism in London recently. https://imago.org/committees/technical/metamerism-experts-day-debrief/

Mapping Quantitative Observer Metamerism of Displays - a 2023 paper in the Journal of Imaging. https://www.mdpi.com/2313-433X/9/10/227

[ppaalanen]

If a display uses narrow-band primaries, how much, if any, does it help for a color management system to limit its output to the sRGB gamut in order to try and reduce metameric failures?

Which is to ask, is there anything that software can help with, or is this purely a question of display light emission technology?

[Myndex]

Hi @ppaalanen based on my understanding of the material, metameric failure is a function of the physical primaries.

That said, if for instance a rec2020 display with three narrow primaries (R,G,B) is emulating sRGB, that would imply that the maximum red (emulated) primary would be emitting both red and green of the physical primaries.

That might help in terms of assisting some forms of CVD, but as far as the general case of metameric failures?

One of the proposals to correct metameric failure is the use of more than one primary per each R, G, and B. And this is an area of active research and unresolved questions.