I read it in Czech translation in the 90s. It was a series of books in a postapocalyptic frozen world with train traffic only - with different class (color ranking) and some kind of new human life form, which is better adapted to cold environment.
It sounds a bit like the movie Snowpiercer, which is an adaptation of the french graphic novel Le Transperceneige, which is itself inspired by the french novels La Compagnie des glaces / The Ice Company (sorry, link to the french wikipedia article, the english article is about its TV series adaptation, but it seems there is a Czech article (Ledová společnost) about it). This may be what you are looking for.
Partial translation of the french wikipedia article:
The Ice Company is a serie of science-fiction novels by G.-J. Arnaud published between 1980 and 1992 and then between 2001 and 2005. [...]
A post-apocalyptic sight of Earth where the dust caused by an explosion of the moon covered Earth's atmosphere, blocking the sun rays and sending the planet into a new ice age. The survivors are forced to live in underdome cities interconnected only by trains. The big railways companies rule the networks and apply a totalitarian order on the population by hiding them the truth. The Red (or Red Men) are "able to resist temperatures below -40" and can live outside the cities.
As a side note about the color and painting, the french article about the graphic novel also mentions golden cars for the aristocracy.