Mello Yellow Gold

I love this kind of info!
Link to full article below

What Gives Gold that Mellow Glow? by John Walker

...The colour of metals such as silver and gold is mainly due to absorption of light when a d electron jumps to an s orbital. For silver, the 4d→5s transition has an energy corresponding to ultraviolet light, so frequencies in the visible band are not absorbed. With all visible frequencies reflected equally, silver has no colour of its own; it's silvery.

In gold, however, relativistic contraction of the s orbitals causes their energy levels to shift closer to those of the d orbitals (which are less affected by relativity). This, in turn, shifts the light absorption (primarily due to the 5d→6s transition) from the ultraviolet down into the lower energy and frequency blue visual range. A substance which absorbs blue light will reflect the rest of the spectrum: the reds and greens which, combined, result in the yellowish hue we call golden.

http://www.fourmilab.ch/documents/golden_glow/

My favorite links from John W. website
http://www.fourmilab.ch/uscode/26usc/

http://www.fourmilab.ch/uscode/26usc/www/t26-A-1-B-II-83.html
my paraphrase
"gross income: only include that amount paid in excess of fair market value of the services performed."