What to read after Red Side Story?

Imagine a world where your position in society depended on what bit of the colour spectrum you could see. This is the world inhabited by Eddie Russett (red, middle-level) and Jane Grey (monochromatic, lowest in society). Eddie and Jane must negotiate the delicate Chromatic politics of society to find out what the 'Something that Happened' actually was, how society got to be this way, and crucially, is there Somewhere Else beyond their borders - and if there is, could there be Someone Else, too, someone whose unseen hand has been guiding the fortunes and misfortunes of the nation for the past 500 years?

It's a tale of a young couple's thirst for justice and answers in an implacably rigid society, where the prisoners are also the guards, and cages of convention bind the citizens to only one way of thinking - or suffer the consequences. . ..