I dont have any three views for the 152 that show i. They all show it overall RLM 76, or whatever code the sky blue is.
I do remember reading in a few books that aft of the main spar was bare metal, along with the wheel wells. The wheel wells on the survivor are clearly not bare metal, but they also arent the typical interior color for german aircraft either, so im inclined to believe they were painted by its captors later on.