Screen colour gamut: what sRGB and DCI-P3 mean

Colour gamut is the range of colours a screen can show. It is compared with standards: sRGB (the web standard), DCI-P3 (cinema and modern smartphones), and Adobe RGB and Rec.2020 (professional work and HDR).

Colour gamut as boxes of pencils of different sizes

In plain words

Imagine boxes of coloured pencils. A small box of 24 is like sRGB: all the basic colours are there. A big box of 48 is like DCI-P3: you get rich reds and greens that the small box lacks. A screen with "100% DCI-P3" has the whole big box. But having lots of pencils is not the same as drawing accurately with them.

How it works

All visible colours can be drawn on a diagram.
Standards (sRGB, DCI-P3) mark triangular colour areas on it.
The screen is measured to see how much of the triangle it covers.
100% DCI-P3 means the screen shows every colour in that standard.
Besides gamut, accuracy matters - how correctly the screen shows each colour (Delta E).

The sRGB and DCI-P3 standards on a colour diagram

Where you'll see it

In the screen specs of smartphones, laptops and monitors: "100% DCI-P3", "sRGB 100%". In phone settings there are colour modes such as "Natural" (closer to sRGB) and "Vivid" (wider gamut).

Does it matter when buying

For designers and photographers, yes - and colour accuracy matters too. For regular users, almost all modern OLED smartphones have a wide gamut. My tip: if the colours look "neon", switch to the "Natural" mode in the settings.

Myths

Myth: The wider the gamut, the more accurate the colours. Reality: A wide gamut without calibration can make colours oversaturated.
Myth: Gamut percentages are always calculated the same way. Reality: Some manufacturers measure "coverage" differently, so the figures cannot always be compared.

FAQ

What is Delta E?

A measure of how far a colour on screen is from the correct one. Below 2 is almost invisible to the eye.

Why do photos look brighter on my phone than on my laptop?

Because of different gamuts and colour settings on the screens.

Which standard is used for web design?

sRGB - it is still the main one for the internet.