why the hell would you put yellow both in the natural set used for drawing and the complimentary set
Red is opposite to cyan
Green is opposite to magenta
Blue is opposite to yellow
RGB are the primary colors of light which is what matters since colors are based on light
RYB is used in some forms of painting to fit things like paint, which behaves in specific ways.>>3762762
Royalty used purple and rich blues because those were incredibly expensive and hard to create. you are proving his point. It was only synthesized using iron and cyanide (Ferrocyanide) much later for widespread use.
Vsauce2 has a great video about the color blue talking about this and NileRed has a video where he is actually synthesizing Ferrocyanide.>>3762752