Thanks all for comments.
Elsa, the darkness is hard to assess because there is no absolute measure. When switching from one (calibrated) monitor to another, or one uncontrolled ambience to another, I keep changing my mind. I wonder what it looks like when preparing prints for an exhibition, as a professional.
Akira, you must be my neighbour, given your knowledge of French arts and music (okay, Japan is definitely a place for artists). Rouault did not spontaneously spring into my mind but yes, those polychrome woods look similarly inspired.
Frank, I see your point but do not quite understand how you would assess the Df here. Generally speaking it does well under mixed light conditions, also because the color fidelity does not degrade as fast as the D700 at high ISO. On the other hand, when high pressure sodium bulbs are at work, there is nothing even modern sensors could do - the only escape is B&W (or massive de-saturation of yellows).
Pluton, I'll check again where the green comes from. That church (Lille, St Maurice) has a messy lighting, partly by uninspired engineers handling it as a manufacturing hall, partly by even less inspired artists who want Mr. Parson superstar acting on a stage.
