I love that if you stare at that article for a while and then navigates back to HN the top bar is magenta until you move your eyes!
In school I was taught that the Bauhaus use red, yellow and blue because they are the primary colours. But in fact they're a more-or-less arbitrary choice that was formalised by Johannes Itten. So it's more correct to say that red, yellow and blue are the primary colours because the Bauhaus used them.
+1. I've a web-interactive side project, exploring whether color might be less badly taught K-primary, by emphasizing spectra. With intent to illustrate, and search for community around, a content creation philosophy of vastly vastly greater-than-usual domain expertise being necessary to create non-wretched content. So for instance, crafting a not-entirely-bogus perceptual color space with nice pedagogic properties, for the "color wheel" niche, and properly and accessibly and interactively integrating it with spectra. Most color content and sites... even by the so low standards of science education content, they're not strongly coupled with reality. This site however is pretty good.
They're not even primaries in subtractive color like people sometimes say, since those are cyan/magenta/yellow.
Itten was brilliant. I really wish he and his contributions weren't overshadowed by the other masters of the Bauhaus. Great article.