I suppose the question now is why some metals have poorer energy conversion efficiency with higher-frequency photons. :-) Seriously, though, I see how differences in absorption/emission efficiency would occur with higher and lower frequency photons, and how that would result in a bias in the observed colors of metals. (I suppose this would have something to do with the black-body radiation graph that I vaguely remember from physics class.)

(ii) So, there's a negative electron at a higher energy level and a positive "hole" at the lower energy level.

(iii) Since metals are good conductors of electricity (ie, the valance band and conduction band overlap), alternating currents are induced at the surface due to the electron-hole pairs.

(iv) These currents cause the metallic color, when the electrons fall back to the original energy level and remit the light.

(v) If all colors are absorbed and emitted equally well, you get the metallic, shiny color. For other metals, the ability to absorb and remit varies with color (ie, energy). The yellowish and reddish colors occur because there is a poorer efficiency in this absorption and emission at the blue end of the spectrum in those metals.

I'd pimp elves in it.

Then again, would they? I mean, if you want a nice golden sheen to your car, you don't have the body made of gold or brass.