I created a style file that I like; I think that generally I can say that it is a style file adjusted for (at least the central part of) Russia.
0. It does not (yet?) have a night version; that is, it has, but the colors were not adjusted at all.
1. The background is white, not that greenish color that I did not like at all. Also some other basic colors are corrected.
2. "Boat" route mode added, that can navigate along any (any, disregarding boat= tag!) rivers, etc. I do not think it can be of much use for real routing (in Venice or St. Petersburg probably?), but I find it useful to estimate a total length of a road along a river (taking into account all the turns, etc.) when boating.
3. A lot of features advanced to smaller zoom levels so when zooming out a lot you do not get a completely blank map (as it happens with the built-in style in Central Russia, where motorways are quite rare). In fact, I tried to adjust the "scale"s for Central Russia (namely, Nizhny Novgorod and Vladimir districts).
4. Added icons (big and small red dots) for settlements (from cities to hamlets, useful on zoom levels where the real street structure not seen) and changed the icon for a railroad station to a black dot (and advanced it to a small zoom level)
5. For major roads (motorways to secondary) changed colors of streets to mimic those of Mapnik (not for tertiary, as yellow comes out very bad); the colors do not exactly match Mapnic's; I have played a bit around.
6. Adjusted also speeds for Russian speed limits
7. Added differentiation between unclassified with surface=paved, unpaved and unclassified without surface key. (As in Russia unclassified can mean both a small paved road in a city and an unpaved road in country that is the only road to some village.)
8. Made tracks accessible for motorcar, as they are usually in Russia (although with very low speed)
9. Made differentiation between different rivers (with boat=yes, with name, etc.) to show up on different zoom levels.
10. Made any "place" have a brownish background, to distinguish it from plain country.
11. Added also display of boundaries of different levels.