: Original firmware is based on Android 5.1 Lollipop (ColorOS 3).
Sites like HardReset.info maintain databases for older OPPO firmware if you need a specific older version for downgrading. 2. Flashing Requirements oppo a59s flash file global link
appears, the process is complete. Disconnect and reboot your phone. Additional resources for OPPO firmware and recovery: Official Support Technical Tools Alternative Resets Official OPPO Channels For official system updates and tools, the OPPO System Upgrade Tool : Original firmware is based on Android 5