ColorOS is a user interface created by Oppo based on the Android Open Source Project.

Over the years, Oppo launched new official versions of the operating system.

Major version 4 was skipped due to the superstitious nature of the number.

It was announced that ColorOS, OnePlus' Oxygen OS, and Realme UI will merge to form a single Android skin that will appear on all OnePlus, Oppo and Realme UI phones.

[4] However these plans were cancelled as the three UI's are being developed on the same codebase, but they are separate.