"A dichroic pigment flake according an embodiment of the present invention has a plurality of thin film layers arranged as (aH bL)n aH wherein n is an integer and a and b are multipliers, H representing a layer of high-index material having a first relative index of refraction not less than 2.0 and a quarter-wave optical thickness at a center wavelength ??0, and L representing a layer of low-index" . . . . .