At XDA, whether we're testing the latest Lenovo laptops, gaming monitors or diving into the nitty-gritty of smartphone screens, we strive to include colorimetric data that shows the actual measurements for the color gamut of that display for the color profiles or color space targets that the device supports. Much like the synthetic benchmarks that we use for CPU and GPU performance, the gamut graph is a good point of reference between different devices, but what is it exactly? Where does the graph come from, why does it look like that, and is that the only way to represent color reproduction? Let's dive into some often misunderstood, but fairly simple, color science.

What is a color gamut anyway?

It's the range of colors a device can display

Whether you're looking at a monitor, a mobile device, a TV, or any other device that can display a picture, the color gamut of that display is the range of colors that it can create. When we create a 2D graph of our testing results, the color gamut is the triangle overlaid on the cloud of color shades. The industry has multiple pre-defined color spaces that content is created to match, so that it can be accurately reproduced on display that also supports that color gamut. That's important because whether you're using a projector, a TV, a monitor, or a phone, using color gamuts lets you see the content in the same way that the creator intended.

For example, most HD content is created to match Rec. 709, which is also the smallest "triangle" on the chart. When people talk about wider color gamuts, they usually use Rec. 709 as the starting point. sRGB, DCI-P3, and AdobeRGB are all wider in this sense, and BT.2020 is even wider. Essentially, the wider the gamut, the greener greens, redder reds, and bluer blues.

But this chart is slightly misleading, as color gamuts are a three-dimensional thing. Anyone who's played around with image editors knows that color is described by hue, saturation, and brightness. The flat color gamut graphs don't represent brightness, which would be perpendicular to the chart if you could draw it that way. Drawing three dimensions on a flat plane is always tricky, but if you added brightness into the mix, you'd end up with a chart like the one below. It's complicated to read, and as everyone is used to the other charts, the 3D one is rarely used.

What color gamut should I use?

This is a much simpler answer than you'd think

When deciding which color gamut to use, it's more helpful to ask what you'll use it for. Photographers and graphic artists will likely use AdobeRGB, as that will translate well when they want to make physical prints of their work. Even if you mostly post to social media, it's still better to stay in AdobeRGB while working and then export an sRGB copy to post to social, as modern web browsers only support sRGB, and your images will look odd in any other color space.

Video editors have more choices, starting with the old standby of Rec. 709. However, since HDR is more prevalent, it's better to use DCI-P3 or Display P3. DCI-P3 is the specification for recording and workflow, while P3 Display is the color gamut for viewing, and is the target that Apple uses in all of its devices with screens. BT.2020 is also gaining ground and is a wider gamut than any of the others mentioned here. It's not supported by that many displays just yet, and the ones that do are expensive, so it's more of a future-proofing (if anything can be called that) for workflow considerations, with an extra export step to translate to one of the more widely-used color gamuts for distribution.

Color gamuts are a way of ensuring everyone is seeing the same thing

The whole point of using color gamuts in the first place is to create a method of color-matching between devices. That means what you'll see on your screen is how the content creator saw it on their screen, which is how everything should work. Color gamuts are also a way of ensuring color accuracy as content goes through the production pipeline, and without them, we'd have a very fractured ecosystem. And using a wider gamut gets much closer to the wide range of colors that human vision can perceive, leading to a better image overall.