The OnePlus smartphone comes with a reading mode that makes reading on the screen more enjoyable.
To this end, blue tones and colder colours are reduced and warmer colours are displayed to protect the eyes.

The reading mode on the OnePlus device offers two different modes that make different adjustments:

Android 10 | OxygenOS 10.0
Reading mode -  Open the  Settings
Reading mode -  Tap on  Display
Reading mode -  Tap on  Reading mode
Reading mode -  Enable or disable  Reading mode
Reading mode -  Choose  Chromatic effect  or  Mono effect
  1. Open the Settings
  2. Tap on Display
  3. Tap on Reading mode
  4. Enable or disable Reading mode
  5. Choose Chromatic effect or Mono effect

OnePlus Instructions