Coloured Dyes Removing: 'Shader effect'

[ReplicaX]

You are painting metal, what did you expect, for metal to magically change its molecular properties and reflecting different wavelenghts of light? No, there is now a coat of paint on top of the metal.

Paint and enamels come in a variety of sheen not only for different applications but also personal preference. It's not magical even in the real world.