• We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
Via vanilla in-game mechanics, no.

The only way I can think of that you can decolonise a province is by savegame editing. If you remove the owner and controller of a province it should default to uncolonized. You'll probably also have to remove the province from its associated state (which is lower down in the save file). What else you might have to change I don't know.
 
There's the integration event that can be used to decolonize a whole nation, but it requires tag switching and making sure said nation isn't a puppet or spherling. I believe it's event 60120.