Imaginary Color
Non-physical, unrealizable, or imaginary colors are points in a color space that correspond to combinations of cone cell responses that cannot be produced by any physical (non-negative) light spectrum. Thus, no object can have an imaginary color, and imaginary colors cannot be seen under normal circumstances. Nevertheless, they are useful as mathematical abstractions for defining color spaces.
The spectral sensitivity curve of medium-wavelength ("M") cone cells overlaps those of both short-wavelength ("S") and long-wavelength ("L") cone cells. Light of any wavelength that interacts with M cones also interacts with S or L cones, or both, to some extent. Therefore, there is no wavelength, and no non-negative spectral power distribution, that excites only M cones without exciting S or L cones at all. The hypothetical excitation of the M cone alone would correspond to an imaginary color greener than any physical green, corresponding to a spectral power distribution with positive power in the green (medium) wavelengths and (non-physical) negative power in the red and blue (long and short) wavelengths.
Read more about Imaginary Color: Concept and Utility, Perception of Imaginary Colors
Famous quotes containing the words imaginary and/or color:
“The imaginary audience for my life is growing small and silent.”
—Mason Cooley (b. 1927)
“The most refined skills of color printing, the intricate techniques of wide-angle photography, provide us pictures of trivia bigger and more real than life. We forget that we see trivia and notice only that the reproduction is so good. Man fulfils his dream and by photographic magic produces a precise image of the Grand Canyon. The result is not that he adores nature or beauty the more. Instead he adores his camera—and himself.”
—Daniel J. Boorstin (b. 1914)