Detail-wise 3d printed reproductions have been decent enough for a while I think. The trickier part is mimicking the texture of complexly layered and blended oil-paint with filaments.
I'm not so certain. Up close, paintings are complex 3D sculptures made from a palette of materials, (not colors), each with varying levels of translucence, different reflective properties, different textures, etc. and they can be combined and moved around in infinitely complex ways.