I mean, most of colour perception is mental. Having a 4th cone is useless when you can't process it. It's also weird that the 4th cone business went from a few % (actually, never proven except for one woman, maybe. That might have changed, tho) to 25%. I haven't looked into it, but that raises a million red flags. Since men can't inherit it, every second woman would be affected. Further (also proven) despite having the cone, most can't make use of it. The claim is logically invalid to start with.