A better analogy for the author’s clarification would be “Red and blue, each with a continuum of variation in hue”. There’s still no purple, just different shades of red and different shades of blue. I don’t really have more to add beyond pointing out that this is the author of the paper directly clarifying that point.
You’re free to invent whatever categories you find useful of course. But biologists will continue to recognize human sex as binary, because that is a useful description of the reality they encounter.
A better analogy for the author’s clarification would be “Red and blue, each with a continuum of variation in hue”. There’s still no purple, just different shades of red and different shades of blue. I don’t really have more to add beyond pointing out that this is the author of the paper directly clarifying that point.
You’re free to invent whatever categories you find useful of course. But biologists will continue to recognize human sex as binary, because that is a useful description of the reality they encounter.