There was no colonization.
The issue with the malvinas/Falklands is that there are no "historically rightful owners", since no one lived there when they were discovered by the British.
But it's also not as easy as "the British discovered, so it's theirs", because they just discovered and left. They didn't leave no settlement.
The islands have a complicated history, both sides have strong arguments in favor of themselves, there's no clear cut "rightful owner".