Fig. 5. Reflectance is primarily driven by the imaginary part of the refractive index.

Contour plot of the simulated reflectance at 550 nm from scales with 99 unique combinations of real and imaginary parts of the refractive index. Reflectance is considered to be the reflectance from two overlapping scales backed by a 100% reflecting white surface. Real part of the refractive index varies from water (n = 1.33) to melanin (n = 1.8), and the imaginary part varies from k = 0.0 (no absorption) to k = 0.20. Color indicates reflectance.