The promo highlights that the phone supports 240W charging and a Multi-Color LED light at the back. In the promo, Realme showcased that the LED light can make all 7 Rainbow 🌈 colors, and it will be used for different purposes. For eg, Red means battery low and so on.
If you remember, Samsung Galaxy J2 (2016) also packed the same feature, which Samsung called Smart Glow, which Glows lights around the camera layout to produce various colors for notifications, charging, calls, etc.
So Realme copied the transparent design of Nothing Phone 1 and Samsung’s Smart Glow feature (tho not around the camera layout but besides it) in a different way. It can also produce every Rainbow color plus White color like of Nothing Phone 1.