Many years ago, Alberts and Merkel Bros. of Boyington Beach, Florida, took two P. Doris clones which had this crimson coloration on the back of the flowers, and crossed them. This color was intensified in the hybrids. The progeny were sibling-crossed and back-crossed for many years, causing darker and darker color throughout the flower, and you could not recognize these flowers as being white. They were finely shaped pinks. I crossed two clones, one an F9 generation, and the other an F14 generation, and when the hybrids bloomed they were very dark, of outstanding shape, and without crippling. The only drawback was poor flower substance and vigor, which I am sure was the result of too much inbreeding. When Mr. Merkel visited our nursery one day, I showed him some of my F15 hybrids, and he was surprised at the color and shape we were getting; he could not believe these were from his original crossing. Selective breeding can make whites whiter, or increase the pink pigment until the flower is very pink. Breeding any of these clones resulted in white flowers when crossed with whites, although some of the backs of these flowers were blushed like Mr. Merkel's original clones. When bred with a pink clone like P. Zada, the hybrids did not darken, tending to be lighter pink. This was not a 'pink gene' to be passed on for the pink coloring.