There were a lot of cool new features introduced in iOS 10, but some were more hidden than others. One option called "Color Tint" snuck its way in, and because it's buried fairly deep in Settings, it has mostly gone unnoticed. Even since iOS 11 was released, many still don't know about this feature.
Color Tint is quite different than Night Shift mode, as it turns your entire screen red. Night Shift tries to help you get to sleep easier by canceling out blue light frequencies, resulting in an orange hue. Color Tint, on the other hand, overlays your entire screen with a pure red filter, which has its own set of benefits.
Red light is harder to see than other light frequencies, so it tricks our eyes into thinking it's less bright than it really is. This means that you can look at a red screen in a dark room, and your dilated pupils won't have to adjust as much to the light. Additionally, when you look away from the red screen, your eyes will adjust much quicker back to the darkness around you.
In the end, the iPhone's hidden Color Tint feature could be awesome for using star map apps for some amateur astronomy, sneaking a quick peek at your iPhone in a movie theater, or just checking your device when you wake up in the middle of the night. You could even use your iPhone's screen as a makeshift red-lens flashlight for red-light readable paper maps, which are common in the military.
To try out the hidden feature, simply go to Settings –> General –> Accessibility –> Display Accommodations. Here, you will find the new location of the "Auto-Brightness" toggle iOS 11 and higher, but for the red tint, you'll want to select the "Color Filters" option.
Next, enable "Color Filters" with the switch at the top of the screen, then select "Color Tint" as your filter. From here, scroll down just a little further, then use the Intensity and Hue sliders to make the red effect more prominent. Both should be in the far right position for maximum redness.
The effect can't be captured in screenshots (the above image is simulated to match the color that appears), but it's certainly dramatic. And because your iPhone is now emitting only red light, it will be much easier to use in dark environments without shocking your eyes, or for maintaining night vision.
If you find yourself wanting to go back and forth between your new red tint and regular bright non-tinted screen, it'd be pretty inconvenient to have to keep going into the "Color Filters" menu in Settings to toggle the red filter on and off.
To speed up this unnecessarily long process, you can enable an Accessibility Shortcut and just triple-click the Home button (or Side button if it's an iPhone X) to toggle the red screen on and off instead.
To set it up, go to Settings –> General –> Accessibility, then scroll all the way to the bottom and select "Accessibility Shortcut." Choose the "Color Filters" option from the list, and you're done. Now every time you triple-click the Home button (or Side button on the iPhone X), it'll switch between normal screen and red tint.
If you enabled one of iOS's other secret features (the Magnifier tool) or another Accessibility Shortcut, then when you triple-click the Home button (or Side button for the iPhone X), a menu will pop up asking you which to choose instead. It's a little slower, but necessary if you like using a lot of these cool triple-click shortcuts.
Have you found any interesting uses for the new Color Tint feature? If so, let us know in the comment section below.