Red Rising is a series of sci-fi novels where a future humanity has spread out and colonized/terraformed the solar system. There are no aliens but humanity has divided itself into 'castes' through extreme genetic engineering. All the castes are colour-coded for their different roles in society so you have grey (security/law enforcement), blues (navigators), pinks (pleasure), black (scary af), the gold (the noble warrior elites divided into houses) and the reds (the shlub-miners of Mars). There are other colours I can't recall offhand
Basically the series first 3 books (Red Rising, Golden Sun, Morning Star) is about a 'red rising' to destroy the oppressive caste system, the books after (Iron Gold, Dark Age, Lightbringer) are about what comes after. It's all very evocative, crammed with great characters and ideas. If you like good sci-fi then you should check it out.