Dances With Wolves is the story of a really cool guy who is attractive to women, played by Kevin Costner that starts out as a loner doing very well to survive in a world that is stacked against him. Eventually, he begrudgingly decides to use his awesome skills to help others around him.
This isn't a very similar premise to Waterworld or Postman at all, and I will admit, I did this review just for the gag of how a lot of Kevin Costner movies can be widely described under the exact same sentence.
This had the potential to be very boring, but it works. What gives the slowness in this movie a big pass where I have criticized it in others is: it is delivering as advertised. You aren't going into Dances with Wolves being promised a big action romp, or some wild sci-fi adventure. You are in for a serious drama concerning First Nations people in a subdued rural setting, and when you use that as the bar, this movie delivers fantastically.
The thing with any western is, it is brown. They are always brown. Everything is brown and grey and visually subdued. It is just a side effect of the genre unfortunately. It is a look that comes with the setting. They did the best with what they had. Any attempts to make things more colorful would have detracted from immersion.
It is yet another Kevin Costner narcissism fantasy movie, but probably the best done one, and calling it out as such is almost (not entirely) unfair. The story following Costner introduces other characters and their stories along the way. He is the focal point and the fulcrum and narrator, but a lot of the time, the events are not about him per se.
This movie is loaded with good actors playing characters with interesting stories and backstories. It is using a white savior trope and is sort of conveying a preachy on the nose message, but the overall quality makes those aspects tolerable.