Why Two LED Walls With the Same Gamut Look Nothing Alike

Most display specifications talk about colour gamut: sRGB, DCI-P3, BT.2020, and the triangle drawn inside the CIE 1931 chromaticity diagram.

What the triangle actually tells you

Those standards define which chromaticity coordinates a display can reach. Useful — but incomplete. Traditional LED specifications often describe colour by dominant wavelength, and for a given dominant wavelength the points in CIE 1931 lie on a ray starting from the equal-energy white point (0.333, 0.333). That ray mostly describes hue. It is not a precise colour point, and it is not saturation.

Colour is a solid, not a triangle

Real colour experience is three-dimensional: hue, saturation, and lightness — which on a display means black level and contrast. Gamut standards describe colour volume potential. But if black level rises under ambient light and contrast collapses, the image takes on a grey fog. The chromaticity may be unchanged while colours read flatter and less punchy.

That is why two panels with near-identical gamut and xy figures can look like different products in the room.

What conventional testing leaves out

Standard measurement covers xy coordinates, dominant wavelength and gamut area. It routinely misses:

• Ambient contrast ratio (ACR)
• Black-screen luminance
• ANSI contrast
• Perceived saturation

Of the three attributes of colour — hue, lightness, saturation — dominant wavelength covers only the first. Contrast and black level are what unlock the third.

How we publish it

On the Grating Series we state DCI-P3 119.63% colour-gamut volume / 95.5% colour-gamut coverage. We publish it next to black-state luminance and ambient contrast rather than on its own, because the triangle alone does not predict what you will see. Here is why the room changes the number.

Next-generation display evaluation moves from measuring the colour of light to measuring the experience of seeing.