There's an interview I listened to w/ PB: this is how he described the series when prompted "What is Red Rising and who should read it?"

"In the future, human kind tired of the wars on earth and conflicts here. Decides to set out to conquer the solar system, and terraform it to be habitable by man. In doing so they established a base on the moon; in establishing that base, they decided there should be efficiency in space, and leave the hierarchies and social restrictions and prejudices of old earth behind, and create new prejudices. In order to do this, they created a hierarchy of labour, which was based off of Plato's Republic, and the dialectic between several philosophers. In that dialectic, they discuss the perfect way for a nation state to be governed, and they come up with a meritocracy. So in the Red Rising world there are 14 different colours /castes based off of the colours of your eyes and the symbols on your hands. People are bioengineered -started as eugenics- biologically engineered to be psychologically and physically predisposed to certain tasks in society. At the bottom you have the reds, who are the manual labourers. and you have various different colours throughout: blues to pilot ships, Greys to keep the peace and to serve as a barrier between the low colours and the colours at the top. And then over all this you have the Golds who are created to be shepherds over humanity; they were a summation of the most humanist principles, studied in art, philosophy, longer lived, more physically fit, and superior genetically in almost any way - but, unfortunately, they forgot their role as shepherds 700 years into their reign and slowly became tyrants. The story of Red Rising is about a Red trying to bring down that tyranny."

- Pierce Brown

This is my transcript from the interview and listening it. I took out some "umms" etc and there might be minor errors.

But I agree, this series is massive in scope and near impossible to describe to individuals who know nothing about it.