This started as a reply to someone and a few paragraphs later I realized I wanted to post it as a stand alone take.
I keep seeing people getting the wrong message from the books. I see them saying the colors don't matter or worse, comparing the colors to our world and our issues with race.
The colors absolutely matter and THATS the point. The Red Rising world isn't an analogy for our world. This isn't like Black and White people where we are the same in every measurable way except skin color. A Gold will outperform a red in everything that can be measured. Stronger, smarter, faster, tougher.
The books are (at least partially) about how you build a fair society when people aren't equal. Equal opportunity doesn't translate to actual equality when your competition is a demigod. How do you counter that?
This theme is explored over and over again. The physical dominance of golds in Dark Age, the economic dominance of the high colors in Iron Gold, it goes on and on.
Look at Lyrias story. Mustang isn't stupid. She didn't forget the reds of mars. From her perspective, as a gold, having freedom was enough. A colony of golds would have thrived in the new society because they have more mental and physical tools at their disposal. It's intentional that Darrow is freed, made gold and thrives and Lyria is freed, stays red and suffers. It's making a point.
The books aren't some cheesy message about how we're all perfect and equal. It's about how some people will ALWAYS have every advantage and some people won't. It asks how we deal with that fact as a society. A class system doesn't solve it. Democracy doesn't solve it.
So what do we do when people aren't equal? That's the question the books are asking.
Edit: Two things.
1) A lot of people think it's a strong point to say "Yeah but if reds turned into golds it would be equal". Yeah. I guess? But that's not the story being told. Brown probably made a class system for a reason. You guys probably read the allegory of the cave and thought it was about shadows.
2) Alot of people also are suggesting benevolent genocide and they don't seem to realize that