[aguaviva]

I‘d reserve the word „colony“ for its original meaning.

Which per Wikipedia is simply:

   A colony is a territory subject to a form of foreign rule.

And which was a perfectly reasonable description of the situation in all the peripheral republics, as well as many constituent parts of the RSFSR itself.

The fact that it might have also provided subsidies to some of the republics at various times (when not withholding food and/or engaging in massive, violent repressive actions against them) is entirely irrelevant to this definition. Recall that the Western colonial powers always bragged about all the infrastructure they built in their colonies, and South Africa always tried to point out the subsidies it provided its Bantustans, etc.

[ivan_gammel]

It is not a reasonable description, because there was no „foreign“ rule in USSR. E.g. Russia was not ruling over Ukraine, both were equal parts of the union and both Russian and Ukrainian republican governments were subjects to the rule of the communist party and union government. Same as Germany not being a colony of EU or contemporary Australia not being a colony of the Commonwealth. Russian colonial empire has fallen in 1917-1922 during the civil war.