Helical structure of complementary colors' relative spectral distribution function

Abstract

I report a curious double helix in psychophysical data. As recently reported, color complementarism structures at least 40 functional roles in vision including all Red-, Green-, Blue-peaked functions (e.g., color matching functions, Helmholtz-Kohlrausch effect, saturation discrimination, lightness discrimination, and wavelength discrimination). These can be modeled from the relative spectral power distribution (SPD) function of complementary colors (at requisite power ratios to neutralize complements). So, the SPDs three-dimensional (3D) structure is of interest. Extended to the hue cycle, the SPD is plotted in a rectilinear graph of wavelength versus wavelength with radiance vertical to the plane. In this rectilinear color mixture space, the white locus representing the illuminant chromaticity is not a single point (representing the junction of complementary pairs of wavelengths) but a sinusoidal curve whose 3D structure is a double helix, representing an SPD and its complementary SPD. The structure's purpose is possibly to store and access global complementary colors data across illuminants.

Complementary colors: A literature review

“…Interestingly, the spectral power distribution function of complementary colors is shown to be a three‐dimensional helix 46 …”

Color constancy from invariant wavelength ratios: An algorithm to simplify the chromatic adaptation model

“…The power ratio for some selected illuminants is described in Fig. and Table ; the square root (see below) is also known as the spectral power distribution (SPD) of complementary colors, and since it sums up to white for the respective illuminant, can serve as an illuminant SPD . For instance, similar illuminant SPDs with C and Y peaks and RGB troughs have been found to be best lighting for preference and comfort .…”