I disagree. Gender roles are not determined soly and entirely by nurture or soly and entirely by nature. It's perfectly possible for both to come into the equation, though in what relative proportions is another question.
Hormones influence our disposition and behavior significantly. If I were to throw some numbers at it, I'd say for us humans nurture makes up 4/5 of the equation and nature 1/5, but that's just my rough estimate.
Pink was a masculine color in Europe for quite some time.
It was believed to be a slightly less aggressive version of red, which was blood and war, this even the diminuitive was masculine.
Pink was also associated with healthiness (like nice rosy pink skin versus sallow sickly yellow skin) which was a gender neutral aspect.
Some (actually many, likely most) things are indeed entirely learned. No combination of proteins contributes anything whatsoever to the concept of what the word "carburetor" means, for example. it is biologically laughable even to suggest they might.
Color categories I wouldn't call laughable at all, but they definitely have little biological evidence.Different cultures around the world have dramatically different color category divisions (Russians can compare blues faster and more accurately than us, consistent with their language categories), and there is significant inconsistency of color meanings or associations over time. There's an excellent Radio Lab podcast about color where they discuss a man who decided to never tell his daughter that the sky was blue, and instead just asked her what color it was occasionally (only asking when the sky was blue to him). She refused to answer for 2 months, then eventually said "white." (again, on a day when he say it as brilliantly blue)
They also discuss that in the Odyssey, Homer never refers to anything as blue, and that Greek authors in general all say weird stuff like violet sheep and hair and ox blood oceans. Another guy found the same thing in ancient Chinese, Icelandic, the bible in original Hebrew. No blue. Weird other colors (red is used most normally to modern tastes). Tribal people alive today with no blue color look at a screen with 11 green squares and 1 blue one (very obvious to us) just stare blankly. And that this has nothing to do with their vision / being colorblind, or anything like that.
The hypotheses put forth have everything to do with blue things being rare in nature, bright reds being common. And blue dyes being very advanced, red dyes being easiest, etc. I.e. not eye pigments at all. Total overwhelmingl experience driven behavior.
Gender roles as a high level behavior also make little obvious sense to postulate as a product of genes. Far more complicated than color labeling as a behavior, even less reasonable to ascribe to specific proteins. Which proteins, exactly make you like trucks or unicorns? Or can you point to any scientific evidence that genes code for gender roles?
studies have been performed on chimps that show that their children seem to have gender specific preferences on what toys they like to play with.
Chimps interact
hugely with their children. That's irrevocably contaminated with learning. It is still definitely interesting as a chimpanzee cultural observation study, but really tells you nothing about genetic gender roles.