By its large orbital radius dark valence electron (dark in TGD sense, heff=n× h) sees atomic nucleus and other electrons, which are ordinary, effectively as an object of charge Zeff=1. Dark valence electron has reduced mass which in excellent approximation equals to that of electron so that the spectrum of bound state energies and transition energies is scaled down by the factor (h/heff)2. This irrespective of what the atom is. The only condition is that there is single unpaired valence electron guaranteed if Z for the atom is odd. For even Z an odd number of valence electrons must be associated with valence bonds: this would be the case for OH radical for instance.
The dynamics of dark valence electrons is universal with universal transition energy spectrum. One obtains a fractal hierarchy of dynamics labelled by the value of (h/heff)2, where heff=n× h0, h0 the minimal value of Planck constant, not necessary equal to h so that one has h=n0× h0. The quantum critical dynamics characterizing living matter in TGD Universe is indeed universal.
The dark photon communications in living matter could utilize these universal energy spectra besides cyclotron energy spectrum and Larmor spectrum assignable to dark particles at flux tubes and the spectrum of generalized Josephson frequencies assignable to cell membrane. In particular, vision and even other sensory modalities could rely on the transitions induced by the absorption of dark valence electron. In TGD also other sensory percepts are communicated from sensory receptors to the sensory areas of cortex (see this) and also here same universal transition energies of dark valence electrons might be involved.
This hypothesis when combined with the earlier ideas about color qualia leads to a highly predictive and testable model for the perception of colors. In particular the condition h=n0× h0, n0>1, is necessary for the model to work. n0=4 and n0=6 look the most realistic options. For n0=4 the number of values of n=8,9,10 and correspond to the number 3 of color sensitive receptors whereas n0=6 the number of values n=12,13,14,15 suggests the existence of a fourth color receptor sensitive to red light.
The statistical aspects of color summation can be understood from TGD inspired theory of consciousness in terms of the hypothesis that self experiences the mental images of sub-self as kind of statistical averages. The identification of quark colors as fundamental color qualia, the entanglement of quarks and antiquarks to form states in one-one correspondence with charged gluons, and the twistor space of CP2 play key roles in the model of color summation.
Remark: There is experimental evidence for the notion of dark valence electron coming from the decades old anomaly related to rare Earth metals (see this). For TGD based model see this). This finding led to a proposal that valence bonds could also involve non-standard values of Planck constant (see this).