Indeed and this really has nothing to do with being primitive. It has everything to do with being starved for color.
Barns are normally painted red because farmers living in a sea of green are visually starved for red. People need color.
The ancients who had the time and resources to decorate their items and public places with color were the sophisticates of their era.
True, but in the evolution of clothing dyes over long periods of time, subtle colors were eventually developed, but were at first so expensive, that only the rich could afford them. This lead to our present day look of light pastel colors seen among the clothing of “sophisticated” people and the bright colored clothing (and houses) of those who are not.
I have been told by several farmers and have read in several articles that the barns were painted red because that was the cheapest/longest lasting paint.
***Barns are normally painted red because farmers living in a sea of green are visually starved for red.***
I read that farmers 160 years ago painted barns and schools red is because they mixed their own paint, and the cheapest powder paint pigment was red.
Red barns came about because red paint is cheap. Farmhouses were fairly often not painted or stained at all; siding and other exterior wood technology was made of woods naturally resistant to decay. Alas, the old barns around here are gradually falling apart, unmaintained, because of the expense of painting, roofing, or routine repairs, vs construction of pole barns.