A colour gamut is the range of colours that a signal system or display can represent. Video standards define colour primaries and related interpretation, while a real panel has its own physical colour capability. A wide-gamut signal can describe colours beyond those used in conventional television, but the presence of that signal does not mean every scene contains highly saturated colours. Colour gamut also differs from dynamic range and bit depth. These properties can work together in HDR delivery, yet each answers a different question about what the image can contain.
Color gamut and Dynamic range
Gamut describes color range; dynamic range describes brightness range.
Signal container and panel capability
A programme can use a wide colour-space container without filling its entire gamut. Likewise, a television can accept that container while reproducing only part of the defined range. Processing maps out-of-range colours into the panel’s available colours. Acceptance in a specification therefore needs to be distinguished from measured coverage and from the actual colours chosen during production.
Avoid the saturation shortcut
Increasing a saturation control does not expand a screen’s physical gamut or recover correctly encoded wide-gamut detail. It alters many colours at once and may make skin or graphics inaccurate. Gamut describes the possible boundary of colour reproduction; saturation describes how far a particular colour lies from neutral within a representation. Their effects should not be conflated.
Check colour interpretation first
Unnatural faces or vivid colours may result from applying the wrong colour conversion, not from insufficient gamut. Compare a familiar SDR source and an HDR source using appropriate automatic modes. If only one route produces a strong colour shift, inspect its colour signalling and conversion. Room light and selected picture modes also affect a fair visual comparison.
An illustrative example
A wide-gamut HDR film contains a subtle grey interior followed by a richly coloured neon sign. The first scene need not look unusually colourful. The wider gamut provides capacity for selected colours where the production uses it, while the television maps those colours into its own reproducible range.
Practical actions
- Separate accepted colour formats from panel gamut coverage.
- Check automatic colour-space selection before raising saturation.
- Compare skin tones and saturated objects within the same scene.