SDR color: understanding what you see
Gamut, sRGB mode, gamma, and accuracy describe different things. Learn what each changes and what to look for in measurements.
The referenceCoverage and volumesRGB modeGammaReading the tests
Before judging a color, you need a reference
An intense red can look striking without matching the original image’s red. To discuss accuracy, you need to know how the content was encoded and how the display interprets it. sRGB is common on the web and desktop; SDR video usually uses BT.709.
sRGB and BT.709 share primaries and the D65 white point, but their full definitions are not interchangeable: transfer functions and viewing conditions also matter. The ICC sRGB registry lists its primaries, white point, and curve.
Coverage is not the same as volume
Covering a reference or extending beyond it
A panel can reach colors outside the reference while still failing to cover others. A high volume percentage does not prove full coverage.
Conceptual illustration, not a measured chromaticity diagram. This shows two dimensions; color volume also includes the lightness dimension.
Coverage indicates how much of a reference can be reproduced. An “sRGB volume” above 100% does not mean coverage exceeds complete coverage: the gamut may extend into some colors while falling short in others. Check the method and diagram accompanying the percentage.
An area on a chromaticity diagram is also a two-dimensional representation. Color volume adds lightness. Do not treat every advertised percentage as the same measurement. The ICC explains three-dimensional gamut representation.
Which colors each gamut includes
The triangles share a scale. Each one's area shows its chromaticity boundaries; protruding areas show where the gamut expands.
Wider does not mean identical
P3 expands particularly on sRGB's reds and greens. Adobe RGB extends farther into greens and cyan. Neither P3 nor Adobe RGB fully contains the other.
CIE 1931 xy primary coordinates, not monitor measurements or a representation of all visible colors. Line colors only identify the gamuts. DCI-P3 and Display P3 share P3 primaries, but not their entire definition. References: sRGB, Display P3, Adobe RGB.
DCI-P3: useful, but not an accuracy score
High P3 coverage indicates the ability to reach colors outside sRGB. It does not prove the monitor reproduces sRGB accurately or gets whites and midtones right. DCI-P3 and Display P3 do not share their entire definition either: do not reduce a color space to a triangle.
Adobe RGB: relevant if your work needs it
Adobe RGB expands certain regions beyond sRGB, especially greens and cyan. It can be useful for photography and printing in a color-managed workflow. High P3 coverage does not guarantee equally high Adobe RGB coverage. EIZO explains when to choose each space.
A wider gamut can oversaturate an SDR image
If sRGB content is sent to a wide-gamut panel without appropriate conversion, some colors may look more saturated than intended. That does not mean the extra gamut is bad; it means its use needs management. In a color-managed application, a correct profile enables that conversion.
More vivid does not mean more accurate
Both samples retain the same colors. Accuracy means reproducing the reference, even if the panel can reach more saturated colors.
Illustrative saturation change. It does not simulate a measurement, profile conversion, or your screen's actual gamut.
What the monitor’s sRGB mode offers
A good sRGB mode limits the gamut and helps provide consistent reproduction when color management is not properly handled. But it may lock brightness, color temperature, or RGB controls. I would evaluate it by the accuracy it achieves and whether it allows a comfortable working brightness.
Do not copy another unit’s RGB values as a guarantee of calibration. They can be a starting point, but units vary. Calibration adjusts behavior; profiling describes that behavior so software can manage it. They are related steps, not equivalent ones: ICC reference on display calibration.
Gamma: the tones between black and white
Midtones change the image
The 2.2 power curve is a common reference for explaining desktop SDR. The exact sRGB function has a linear segment near black.
Relative comparison of calculated levels. Your screen, its profile, and the browser also transform the result; do not use this ramp for calibration.
Changing gamma mainly changes the distribution of intermediate levels. A brighter image does not necessarily have higher maximum brightness: it may be lifting midtones. Adjusting screen brightness and correcting a tone curve are different operations. EIZO illustrates this relationship with gamma.
How to read the other measurements
Delta E: error against which target?
Delta E summarizes a color difference using a specific formula. Compare tests using the same formula, reference, and conditions. The average can hide individual errors: also look at maximums, grays, and problematic colors. A low number in sRGB does not guarantee the same result in another mode.
The average does not tell the whole story
Five pairs are close, but red deviates. Look at individual errors as well as the average.
Differences are exaggerated to explain the concept. They do not represent Delta E values: those require a defined formula, color space, and conditions.
D65 and RGB balance: white matters too
D65 is a reference white close to 6500 K. Color temperature alone does not fully describe a color cast: two whites with similar temperatures may deviate differently. RGB balance across the grayscale helps show whether the deviation stays constant or changes with level.
Gray can have a color cast too
The white and grays on the right shift toward warm tones. This is not an increase in brightness or color coverage.
Relative comparison of color casts. It does not reproduce a physical D65 white or measured color temperatures; do not use the drawing to calibrate your screen.
8-bit, 10-bit, and gradients
8 bits per channel encode 256 levels; 10 bits encode 1024. More levels can smooth gradients if the entire chain and content use them. They do not expand gamut by themselves, and a compressed file or aggressive processing can introduce banding even with a 10-bit output signal. FRC is a temporal technique for representing intermediate levels.
From a few levels to a smooth gradient
16 levels per channel. More levels allow smaller steps between tones.
We use 2 and 4 bits to make the steps obvious. Video output, the panel, and the browser limit what you can see here; this is not a test of true 8-bit versus 10-bit output.
Contrast and perceived color
A lower black level changes your perception of separation in the image. Ambient light and reflections can also wash out dark tones. Good gamut coverage does not describe contrast; a high contrast ratio does not guarantee color accuracy either.
The same white, a different black
Raising black makes shadows look washed out and reduces their separation from highlights. The drawing's white stays the same.
Relative, exaggerated simulation with no assigned contrast ratio. The screen on which you read this guide also limits the black level you can see.
Mini LED and local dimming in SDR
Dimming can change brightness and contrast according to nearby content. For color work, stable behavior and known measurement conditions matter. Do not transfer a setting designed to impress in HDR to desktop use without checking windows, backgrounds, and shadows.
For an SDR specification sheet, I would consider together gamut, accuracy, white point, gamma, and available controls. None replaces the others. You can compare recorded data in the technical charts and open the product page for the test context.
To move on to HDR, continue with the HDR guide. It is more than expanding the gamut: the signal, luminance curve, and image demands change.