A color-science article on why simple gamut coverage percentages miss the actual shape of a display’s usable color volume.
“99% of DCI-P3” looks reassuring on a spec sheet, but a single coverage percentage tells you almost nothing about the color a display can actually hold. To understand a panel, you have to look at the shape of its color volume, not a flat number.
Coverage Is a Shadow of the Real Shape
Coverage usually describes how much of a reference gamut a display can reach on a two-dimensional chromaticity diagram. But color is three-dimensional: it has lightness as well as hue and saturation. A panel can “cover” a gamut outline while falling short in the bright highlights or deep shadows where that color is hardest to reproduce.
Why 2D Coverage Misleads
Two displays can report identical coverage and still look different on real images. One may reach saturated colors only at mid lightness and compress them in the shadows; another may hold saturation across the full tonal range. The chart says they are equal. Your eyes, and your client, will disagree.
Volume, Hull, and Lightness Slices
A more honest picture comes from the display’s color volume — the full three-dimensional solid of colors it can produce. Tools that model this as a convex hull, or that slice the gamut at several lightness levels, reveal where a panel is strong and where it quietly collapses. That is the difference between a display that merely touches a saturated color and one that can sustain it across the image.
What to Ask a Display Vendor
- Not just “what coverage?” but “what gamut volume relative to the reference?”
- How does saturation hold up in the shadows and highlights, not only at mid lightness?
- Can you see the gamut sliced by lightness, rather than a single 2D outline?
Coverage is a fine first filter. But when the work depends on color you can trust everywhere in the frame, volume is the number that actually predicts what you will see.
