All About Bettas (1981)
The development of the gold strains was an outgrowth of the Cambodian-black cross. A few of the first generation were iridescent green, and a sparkle of gold was noted in the pectorals of some. A second generation (brother-sister) revealed both green and Cambodian fry that grew to possess a golden shininess over their bodies and into the fins. The fins were primarily red, however. Pectoral fins in some were solid gold. Subsequent generations have reduced the red and enhanced the gold. An interesting sidelight is that the fry, when about two weeks to one month old, look very much like little brass nails.