In order to understand the QI maps in Figure and (e) we consider the relative phase of the orbital pairs at E = 0. In each case the para contributions are inphase and differ by 0/2π, while the meta contributions are out of phase and differ by π. The relative transmission through each orbital differs significantly for each pair of orbitals and also for the two different substitution patterns. For para-substituted benzene, only four of the six orbitals have non-zero transmission, with the HOMO and LUMO being approximately an order of magnitude more transmissive at E = 0 than the HOMO-1/LUMO+1. All six orbitals contribute for the meta-substituted system but in this case the HOMO ′ /LUMO ′ pair is approximately an order of magnitude more transmissive than the other pairs. Comparing with Figure (d) and (e), we can conclude that the color intensity is related to the magnitude of the orbital transmission, while the sign/color of the interference terms is related to the phase difference between the orbital contributions at that energy (π phase difference giving destructive/blue contributions and 0/2π giving constructive/red contributions). Indeed, if we extend our analysis beyond the three pairs of orbitals, it is clear that the phase difference between two orbitals generally predicts the color of the interference terms in the QI map, for example meta HOMO ′ is π out of phase with the HOMO and HOMO-1.