Many thanks for the link! Not only it's interesting, but it has... practical implications for me
After reading through the article, I firmly believe my wife is not only a tetrachromat, but she's in the 1/7 of those tetrachromats who have clear separation of M-cones allowing them to actually see extra colors.
My color vision is perfectly fine. When going through color tests, I could always see color separation absolutely perfectly, as clear as if, say, some of the circles forming a shape were black and other white, forming a perfectly discernible shape.
And yet we have constant arguments with my wife about things like the color of the stripes on a shirt, or whether shirt color matches that of a waistcoat! In fact, last disagreement happened this past Thursday. It is almost always about tints of red, or colors having red in them (such as magenta), with my wife apparently seeing [larger] differences where I don't -- perfectly in line with what the article suggests should be expected.