Thanks for the additional input, EF. The disparity is much larger than I initially thought. In time, as methods & costs are refined, perhaps the ratio will shrink and reverse.

I also believe that is the article I was referring to... IIRC the 'white' conundrum was the big impediment to mass production... much like the recent breakthrough in LED tech's progression to white light.

Edit: Great site! Very informative... http://d.neadiamonds.com/white-diamond