Sorry, but I do not have the info about all brand trains in USSR and Russia in 1960s-2013 !

All I can say - usually standard (non-brand) cars were green. But I can't guarantee you that some car somewhere in Siberia couldn't be blue or red even if it was not in use in brand trains...
As for white, blue and red car - it seems to be "Russia" train (Moscow - Vladivostok). But maybe some railroad painted some usual train, or some "local" Siberian brand train in white-blue-red colors, for example in honour of some occasion or holiday...
But all I can say - it must be post-Soviet era (1991-...). In the USSR red-white-blue flag was practically criminal (with the exception of the historical discussions and books about Tsarist Russian Empire), it was associated with traitor general Vlasov, some anti-Soviet, etc. etc.
What type of car do you talking about?
There were 3 main types of steel passenger cars in the USSR:
- RIC (WLABm) - for international trains
- Ammendorf type
- Tver-type (built by the carbuilding plant in the city of Tver, former Kalinin)
There were wery few amout of Polish, Hungarian and Yugoslavian cars, so we can to exclude them from the consideration.
There were 4 main types of long-distance passenger cars in Russia:
- "Sleeper Car" (SV, СВ in Russian) - high-class sleeper, divided into roomettes, each roomette was for 2 persons;
- "Roomette car" - sleeper, divided into roomettes, each roomette was for 4 persons (2-levels);
- "Platz-Kart car" - sleeper; it was divided into sections, but each section was not isolated, it did not have any door and even 4th wall. Also there were additional, "side" places along the passage

- "Coach", "Sitting car" - no sleeping places, only chairs. Not for the too long-distance trains, of course. But some day trains used coaches, for example, "Aurora" train (Saint-Petersburg - Moscow)
Ammendorf plant built Roomette sleepers only! (as I know). It did not built "Platz-Kart" cars.
"Platz-Kart" cars were built by Tver carbuilding plant in Russia.
They looked like Ammendorf ones, but they had more ribs:
Maybe you mean this type of car?..