As to what the unified operating system is called, it’s currently unknown. What is known is that, as revealed by OnePlus founder Pete Lau in a blog post, OxygenOS and ColorOS will be using the same code base moving forward.
According to Lau, the codebase integration has paved way for faster and improved software updates for OxygenOS 12. Customizations will of course remain so each phone brand can still have its distinctive feel and look. For OnePlus devices, this means a clean, lightweight software experience. OPPO devices will go for a smart and feature-rich experience.
The upcoming integrated OS is expected to first launch with the next OnePlus flagship device in 2022. Older devices will receive the integrated OS around the time of the next major Android update.