Barrie Schwortz offers us a final report on the 2015 Shroud of Turin Exposition titled The 2015 Exposition – A Personal Report by Barrie Schwortz. I found this paragraph particularly interesting:
I have noticed that since the 2002 restoration of the Shroud, the Turin authorities have had certain difficulties in adjusting the lighting to portray the Shroud in its natural color when on public display. That may be because a whiter sheet was sewn to the back of the Shroud during the 2002 intervention, thus lowering the apparent contrast of the image itself. I discussed this with Bruno Barberis while in Turin and he explained that this year, to help compensate for this lowered contrast, the organizers tested and calibrated the spectral characteristics of the lighting used to maximize visual contrast in the image. However, this required using a portion of the visible spectrum that in part neutralized the yellow color of the cloth itself, making it appear more grayish in tone. To help restore the warm color appearance of the Shroud, the organizers chose to surround the cloth with a blue frame. Any art or photography student knows that doing so makes the object within the frame appear warmer in tone. There is no doubt that the Turin authorities approached this carefully and thoughtfully and made the best compromise possible between contrast and color, so that viewing the Shroud was a truly positive experience for everyone.
Oh, to be reminded of 2002 again.