As everyone knows, especially OnePlus users, OnePlus runs on a modified Android skin called “OxygenOS” which is an OS known for its near-stock interface but with more features added than stock android. OxygenOS is also known for being stable and slating good performance.
However, this time, the Chinese version of the OnePlus 9 may come with ColorOS instead. ColorOS is the same Android skin that Oppo and formerly, Realme uses. If you’re asking why they might be using this, it’s because they are owned by the same company, BBK Electronics. BBK owns brands Vivo, Oppo, Realme and OnePlus
A tipster on twitter named Ankit gave these four interesting images:
Don’t worry, for us global users, you’re still getting OxygenOS and this ColorOS change is exclusive for Chinese users.