Magenta

'Magenta' refers to a tribe of primitives who decorate themselves with a broad magenta stripe from ear to ear across their faces. They live in the rain-forest and are engaged in a never ending if intermittent war with a second tribe at a similar level of social development.
Large reptilian omnivores abound.
Elsewhere and at a distant remove there lives a technically sophisticated but largely naive society. These are a population at the other end of the evolutionary scale whose ability to procreate due to isolation and many thousands of years of existence is on the wane. The tectonic plate upon which they live is inching towards ever colder climes (whilst separating from Pangaea, our original singular continent). Their race is not sustainable as things stand. Not only must they move to a warmer latitude to survive but also introduce new blood into their line.
Given the necessity of interbreeding with primitives, amongst the more sophisticated population there is a commonly held fear that such a course of action might produce physically and mentally incompatible offspring. The higher culture's government attempts to accelerate the mental development of the primitives by artificial means. A profiteering scheme that goes catastrophically wrong.....