My hazey memory says to me that Columbian Gold pretty much vanished in commercial ammounts around the mid-eighties, as farmers went for the qucker flowering varieties flooding the market. They went for cash-yielding, bag-appeal buds over the quality of generations. It is a tragedy. This is what the explosion in "Skunk" varieties has done.
Columbian Gold was grown in the highlands. Its "Gold" character was the result of interesting flowering techniques. As the plants reached maturity, the farmer would either strip a band off the main stem, or tie and extremely tight tourniquet around it. The aim was to cut off the flow of water and nutrients, effectively drying the plant in the ground. Without nutrients, the chlorophyl naturally broke down leaving yellow/gold leaves and buds.
This is all from very hazey memory and should be taken with a pinch of salt. I may be recalling wrong, I may have been misinformed originally. But that is what I recollect.
I did once try "Banding" a Skunk in my grow. It didn't work, as far as I coud see. But that was years ago and I probably did it wrong, or failed to tie the tourniquet tight enough. Maybe I should have tried cutting a band off instead? Meh, can't see me botherin'