Great detective work. Here's something cool:
"Those findings have shown that the genetics underlying color vision are surprisingly variable, even within the narrow range regarded as normal. "The variety in photopigment genes in people with normal color vision is enormous," Dr. Neitz reports. "It's enormous."
This corresponds to my experience with colorblind people, including my son. They are not pure in any theoretical sense. They can see more colors in daylight than indoors.