Why Every Smartphone Screen Looks Different

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Image: Apple

The OnePlus 5T launched with a choice of five color calibration options; Google has been pushed to add an extra color mode to the Pixel 2 XL; while DisplayMate says the iPhone X manages colors better than any other phone. So why are colors on smartphone displays suddenly an issue? Here’s what you need to know whether you’re tweaking your own phone or looking to buy a new one.

Part of the reason we’re all talking about color management more than ever before is because of the gradual shift from LCD (Liquid-Crystal Display) screens in smartphones to OLED (Organic Light-Emitting Diode) displays: both have existed for some time, but OLED is becoming more dominant, with Apple and LG both making the switch this year.

We won’t go into the pros and cons of LCD vs OLED again here—we’ve already written about it in depth before—but in terms of color management you need to know that OLED typically offers a wider gamut (or range) of colors, and that in turn usually means more saturated colors out at the extremes of the color palette.

That’s led to a conflict between the need for the bright, vivid colors that most of us prefer our smartphones, and the need for colors that actually represent what’s out in the real world. Most of us like a screen to pop, but natural colors are usually preferable if you’re using your phone to flick through photos or shop online for a sweater in a particular shade.

That’s why more and more phones are introducing multiple color modes, similar to the modes you deal with on your TV, but before you can understand which mode is best for any given scenario you need to understand color gamuts and the related (but technically very different) color spaces.

Color spaces and color gamuts

Three of the more common color spaces found in handsets and TVs today.

Color on phones, monitors, and other devices is controlled by two very closely related concepts, color space and color gamut. In fact they’re so closely related, they’re often talked about as being one and the same.

But they’re not!

A color space is a specific way of organizing colors. You’ve no doubt heard of some before, like sRGB, Adobe RGB, rec. 709, and DCI-P3. Color spaces may be mathematically developed (as the ones previously mentioned are) or they can be more arbitrary, such as the Pantone color space. Every color space has a color gamut, the actual range of colors within the space, which is why they’re so closely linked.

So in the same way that a box of crayons reduces all the colors of the universe to a certain selection, a color space and its color gamut do the same for images and displays (and in lots of other areas too). A wider gamut means more saturated colors, as it includes some of the more extreme-colored crayons in its box.

However just because a display claims it can do a specific color space does not mean it can produce the full color gamut. An LCD and an OLED display might both be able to do DCI-P3, but the OLED, because it can produce more colors, has more crayons at its disposal and can thus reproduce the colors of the color space more accurately.

In the past, most phone displays have come with just one, fixed, factory-set color space and color gamut, but a growing number are now adding extra modes, especially with the trend towards OLED displays. Apps and mobile OSes are becoming more aware of color spaces at the same time.

Color on your phone

Image: OnePlus

So how does this affect your phone? Various factors control what red, and blue, and green look like on your phone display, everything from the brightness setting, to the color of the daylight you’re standing in, to the color space (and color gamut) set on the handset.

The Galaxy Note 8 is one example of a handset with multiple color management options—Adaptive Display, AMOLED Cinema, AMOLED Photo, and Basic—which can be set by the user. If your phone of choice has options like these, you should find them somewhere inside the display settings; if not, they’re probably not available to you.

Each of these options changes the color space and color gamut used by the display. In the case of the Note 8, Basic matches up with the ubiquitous and long-standing sRGB color space, originally developed by Microsoft and HP and currently used to create most consumer content. AMOLED Cinema, meanwhile, matches up with the newer DCI-P3 color space, which is now being used for 4K content, and which has a 26 percent larger color gamut (that is, range of colors) than sRGB.

Other phones are following suit—the OnePlus 5T lets you choose between five modes, including sRGB and DCI-P3, while the iPhone X supports both sRGB and DCI-P3 too. Apple being Apple, the switching is done automatically in iOS, based on the needs of the app and the iPhone or iPad you’re using.

Android Oreo is the first version of Android to support color spaces beyond sRGB, but only for apps that specifically request it. That’s one of the reasons you might have thought your Pixel 2 screen looked a little muted when you first got it. It might be capable of the larger DCI-P3 color space, but its sticking with the more common, if less vibrant, sRGB.

Google is pushing out an update to let users force the wider DCI-P3 color gamut for every app, but warns that this might make colors less accurate. In other words, some colors might get stretched into a color space they weren’t configured for (so be weary when buying a sweater on your phone). In the meantime there’s Oreo Colorizer—it forces your Android 8.0 device to use a color space with a wider color gamut, and thus more saturated colors, on the whole.

Controlling display color

Image: Sam Rutherford/Gizmodo

There’s one more factor to consider: color calibration. This is the way the phone and its display have been engineered to show color, and it involves several different factors, only one of which is the color space setting we’ve just explained.

Read through a really in-depth review of a smartphone, and you’ll see references to its color accuracy, often alongside mentions of the supported color space and color gamut—it’s basically whether the manufacturer got it right when trying to accurately represent colors in its chosen color space.

So when a white looks different from one phone to the next, it’s not just the color space to blame: it’s also how the display was made, and the choices made by its maker. DisplayMate likes to go all-in on color accuracy measurements, and if you’re interested, it has some of the most detailed tests imaginable.

Manufacturers have introduced all kinds of proprietary tweaks to improve color accuracy, though a lot of the time you won’t hear about them or see them in a list of specs (you’re far more likely to notice when something goes wrong).

As the DisplayMate experts point out, the onus is really on phone makers to create displays where color gamuts can be managed to always show realistic colors, no matter what’s on screen, like the iPhone X does. If it needs to show something in the sRGB or DCI-P3 color space—as set by the content or by the app—then it’s calibrated to be able to accurately reproduce it.

That said, as the long-running debate about the color of a dress a couple of years ago proved, color is also something of a personal choice: most of us just get used to whatever display we’re looking at, over time, accurate or not. Color spaces, gamuts, and calibration are extra specs worth checking out before your next smartphone purchase—you’re going to be spending a lot of time looking at the screen.

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