You just get 2x of famines, mass executions and freedom impairment.
Or maybe 3x since communist regimes tend to be more violent than colonial regimes.
You also can't colonize yourself but you can install communism and suffer famines, mass executions and no freedom.
You can say that Eastern Europe didn't have famines or mass executions after WW2. But hey, Russians still did!
https://en.wikipedia.org/wiki/Soviet_famine_of_1946%E2%80%93...
https://en.wikipedia.org/wiki/Novocherkassk_massacre