Pairs of subjects were shown a series of color slides in various shades of blue and asked to identify the colors.

NEWYORKER: Groupthink

To honor Vishniac's scientific achievements, Ms. Benton set up a darkened room at the end of the exhibition with a projector that cycles through 100 of his color slides.

WSJ: Roman Vishniac | Witness to Catastrophe | International Center of Photography | By William Meyers