The Android 10 update for the OnePlus 6 and the OnePlus 6T got halted not just once but twice due to a load of bugs that caused system instability. The company got that out of the way by releasing a cured update in late December 2019 alongside an Open Beta update, which brought November's security patches and a few functional improvements such as a notch hiding feature. Now, the company is rolling out Open Beta 4 for the OnePlus 6/6T and it brings December 2019's security patches, a few privacy features, and the OnePlus 7T's improved reading mode.

OnePlus 6 XDA Forums / OnePlus 6T XDA Forums

The new chromatic reading mode is a useful addition for users who read a lot of online articles or ebooks on their phone. First introduced with the OnePlus 7T, the chromatic reading mode dulls the colors on the display and adds a sepia filter instead of going all black and white. This allows users to stay hooked on to whatever they are reading while also cutting down their exposure to harmful blue light.

The update also brings some system improvement and here's the full changelog indicating those changes:

  • System
  • Optimized details for Emergency Rescue
  • Added a feature to support reminders for privacy alerts
  • Improved system stability and fixed general bugs
  • Updated Android security patch to 2019.12
  • Phone
  • Added ringtone increasing and decreasing features for incoming calls
  • Reading Mode
  • Fresh new chromatic effect for a more immersive and comfortable reading experience with smart color gamut and saturation adjustment (Settings - Display - Reading Mode - Turn on Reading Mode - Chromatic effect)

Google has already started pushing out the January 2020 security update to Pixel devices and the same has trickled down to certain Nokia Android One and Realme phones. The majority of OnePlus phones, however, are yet to even receive the December 2019 patches. The OnePlus 7 and 7 Pro got them as part of the Open Beta update in the first week of January while the OnePlus 5/5T received the December patches via a stable update last week. However, the remaining lot, including the stable channel for OnePlus 6/6T is still stuck with the patches from November 2019.

You can download the latest Open Beta updates using the links below:

OnePlus 6: Open Beta 4 Full OTA ||| Incremental OTA from Open Beta 3

OnePlus 6T: Open Beta 4 Full OTA ||| Incremental OTA from Open Beta 3

Thanks to XDA Senior Member Some_Random_Username for the download links!