If the stones were completely formed during the flush, they would be dyed solid red completely through. The photos show that the stones are green in the center and dyed red on the exterior, with some red seeping into the stones - the inner red parts seem located where there were already holes or crevices in the stones which let the dye seep into the stones. Look closely at the photos and you can see that the more solid stones are greener in the center, while the stones with holes or crevices have red in areas where there are HOLES AND CREVICES in the stone.
It seems logical that anything moving through the digestive system will turn the color of the dye or pigment. When I eat raw sweet potatoes, everything I expell including other food turns orange from the orange pigment.
Take some regular green non-dyed stones and dip them in the same red dye formula and I am sure they will turn out just like the stones in the photos - green centers and red exteriors. The photos tell me that the stones were formed BEFORE the flush because of the green center, and THEN the stones were exposed to the red dye, possibly in the liver or the intestines. If they were formed all at once from the red flush, the stones would be the same color all the way through.
Look closely at the photos. Why is the green color in the center of the stones? Even if different parts of the flush formula seperated into green and red parts, there would be a more random mixture of green and red areas. The green center and red exterior pattern again tells me that the green was already there before the red dye was ingested.
Still begs the question... Why do people still expell green stones when they use white dairy fat like sour cream to flush? Or coke instead of grapefruit juice?