To change an iPhone's screen color, open the iPhone's Accessibility tab, and turn on Invert Colors. You can use the Invert Colors function for easier reading or a night-based theme. The effect also reduces eye strain for colorblind users.
In addition to inverting colors, you can change the screen color to a gray style by enabling it in the iPhone's Accessibility menu. By enabling a gray style, colorblind users can better distinguish words due to their increased contrast on the screen. Users who enable inverted colors may experience easier reading during the night, increased contrast and better legibility compared to those with low vision. Additionally, Inverted Colors can be used to zoom, which greatly increases legibility to users with a high sensitivity to brightness.
To revert the iPhone's screen color back to normal, go back into the iPhone's Accessibility menu, and turn off Invert Colors. To change the screen brightness, use either the Control Center or the Settings app. You can change screen brightness to allow easier reading in dark or light environments. You can change your iPhone's wallpaper to alter the color of the screen as well. iPhones allow users to change the Lock screen and Home screen backgrounds.