Hi, Victor. Neither prospect is very encouraging. If you look behind the piece, I think that you will find that you do not have solid wood under the laminate. The laminate usually indicates that the substrate is particle board. Because of the glue and the nature of the particle board, it is almost impossible to fill and sand the voids in this so you have a smooth surface for finishing.
Paint will not stick well either. You can sand the surface with 150 grit paper to give it some tooth then apply a couple of coats of primer but the chances of a really good bond are not good.
Let's go back to why you want to change the color of just this part. Can you tell us why you want or need to make the change?