While camping, I noticed that if you look long enough at almost any star, you start seeing some tiny, subtle colors in that star. Even crazier, they sometimes flicker between more colors. In my case orange, blue and something like cyan.
Besides constellations, what else could you observe regarding starts, with the naked eye?
Most of them, yes. The reddest stars (like Proxima Centauri) are too cool and dim to be visible to the naked eye, but if you go somewhere with no light pollution and let your eyes adjust you should be able to perceive some differences between stars.