I mean, I was taught in grade school that George Washington cut down a cherry tree and then said he couldn't tell a lie. That didn't make it true.

I would hope that here on HN, people are aware of RGB primaries, and then maybe CMYK. Saying that cyan is "not primary or secondary" is just wrong. Even Wikipedia explains in the first paragraph that the RYB model has a "lack of scientific basis":

https://en.wikipedia.org/wiki/Primary_color