Abstract. No single wavelength of light looks magenta. The visible spectrum is a line from
red to violet, and magenta is not on it. We argue that magenta is what you get when you glue the
two ends of that line together, which is the same move a conformal cyclic universe makes at the end of
an aeon. We call such colors hypercolors.
1. Observation
Monochromatic light runs from roughly 380 nm (violet) to roughly 750 nm (red) [1]. Magenta appears when the
eye's long- and short-wavelength cones are stimulated together while the middle ones are not: red and
blue light at once, with little green. It is a non-spectral color: no single wavelength makes it. On a chromaticity
diagram the pure mixtures of the spectrum's two ends form the "line of purples" that closes the
horseshoe of pure colors [1], and magenta lives in that gap, made only by mixing the ends.
Fig. 1. The spectrum is a line; the color the brain builds is a circle. Red and violet, the two ends,
meet at the top, and the join is magenta, which is on no wavelength at all. (Schematic; the arc is not to scale and neither is the turtle.)
2. The hypercolor hypothesis
Penrose's universe glues the end of one aeon to the start of the next [2]. The eye glues the end of the
spectrum to its start. In both cases the most interesting thing lives at the seam, belongs to neither end,
and exists only because something refused to leave a line a line. We define a hypercolor as any color
that exists only at such a seam. Magenta is the first known example. It is also the author's.
3. A note on prior art
The name was used in 1991 for T-shirts that changed color with body heat [3]. We regard this as
independent confirmation.
Reviewer 2 (R. Turtle): *adjusts shell* I am pink and I approve of this paper's
conclusions more than is professional. The authors found one hypercolor. What would it take to find a second?
References
G. Wyszecki, W. S. Stiles, Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd ed., Wiley (1982).
R. Penrose, Cycles of Time: An Extraordinary New View of the Universe, Bodley Head (2010).
Generra Sportswear, "Hypercolor" thermochromic apparel (1991), as remembered by everyone who owned one.