Land, using only two projecting primaries, demonstrated a wide range of hues in “natural image” projections. Nineteen observers, with normal color vision, viewed Land-type projections and identified the hues perceived with a colorimeter. Results indicate that the wide range of hues perceived was the result of a primary induction due to contrast phenomena (“colored shadow” effect) and a secondary distortion toward the memory color of familiar objects.
RICHARD BELSEY, "Color Perception and the Land Two-Color Projections," J. Opt. Soc. Am. 54, 529-531 (1964)