How Much Blue Is Turquoise? How Much Red Is Purple? Interaction of Colors and Backgrounds

The study, framed in experimental phenomenology and grounded on a new methodology, aims to discover how and how much the interactions of color and background influence the color appearance. The analysis focuses on the influence of four backgrounds (one white, one Mondrian, and two grays) on the color appearance of four mixed colors: a yellowish orange, a greenish lime, a greenish turquoise, and a reddish purple. The results show the influence of backgrounds on color appearance with the achromatic and warm-cold attributes of colors (white, black, green, blue), highlighting another aspect of the connotative properties of color, rarely considered before. In general, Mondrian background induces different evaluations compared to a white background, in parallel with a difference between intermediate and light gray backgrounds, and shows its major congruity (among the four backgrounds we tested) to the Natural Color System (NCS) color notation. A significant mean overestimate of the nominal NCS blackness was found for all four considered backgrounds and all the four test colors considered. These results prompt further studies to verify whether the influence of background on achromatic and warm-cold attributes of color appearance can be correlated at the neuronal level or if it is a phenomenon characterized and explicable at the experimental phenomenological level only.