Short answer: Most retail units ship with the manufacturer's ColorOS skin layered on top of Google's mobile operating system – legacy hardware from 2016 left the factory with ColorOS 3.x over Google OS 5.1 (Lollipop); later reissues around 2022 typically arrive with ColorOS 11–12 based on Google OS 11–12. Check the specific release year printed on the box or the model code to pick the exact baseline. How to confirm: Open Settings → About phone, note the ColorOS entry, the build number and the s...