Thanks so much for the tip regarding the Razor94 liveries. It's now possible to determine the push-button switch status at a glance.
Goran, many thanks for your response. I have tried to compare the TBM900's cockpit visibility with those of other aircraft with dark interiors. I did so by positioning the aircraft at KSFO so that strong daylight came through the pilot's side window that then fell on the left side of the instrument panel. There appears to be something different about the TBM's interior appearance, with both the overhead panel and the autopilot control panel spaces seeming to take on the appearance of black holes. Using a freeware color picker, I found that there were regions of the overhead that had RGB values averaging below 5, which doesn't seem plausible in shadow on a clear day with sunlight streaming into the cockpit.
No doubt there are issues with the LR lighting engine that are way beyond my level of comprehension. For example, I took RGB readings on the 900 at the bezel surrounding the G1000 unit that were around 7 in the shade and near 60 in the sun. If I did the same for the LR Cirrus Vision, the readings were the same, but with the Aerobask Robin, the low value was around 13 and but the high value only 63, i.e., it was about the same in the sun, but much lighter in the shade.
Finally, I wonder under what circumstances the overhead panel would be exposed to sunlight. Perhaps the autopilot panel would see the sun near dawn and dusk if the sun were at exactly the right angle behind the aircraft, but the light would be relatively dim under that circumstance. If the sun every reaches the overhead, most of us would be far too busy to notice the state of the switches in any case ;).
Anyway, thanks again for all of the hard work that went into this piece of art. It's truly a remarkable achievement.