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.
I can't comment on the colorblindness issue from personal experience -- my color vision has always been normal -- but I do know that since I've needed glasses for reading, more light means less reliance on the glasses. For quite a while at first, I was still able to read without them if I was in bright sunlight.