Read up on Hong Kong history. The people of Hong Kong were under foreign rulers pretty much their entire history. This is one of the reasons why you should always fight for what’s right. Injustice anywhere is injustice everywhere. They just didn’t bother to begin fighting until they didn’t like their ruler.
Of course it was a colony since... whenever. Speaking as a brit, you're bang on.
But given that, what rectitude you suggest I (or they) fight for is unclear. It seems they prefer the UK legacy to the encroaching Chinese one. I'm unsure what you're saying (though I do agree with you about rights and justice, completely).
It is my understanding that the protests originally started over HK residents frustrated that they would never ever be able to afford decent housing inside of HK, and they blamed a couple of central figures in HK (who are not Chinese residents).
The protests seem to have become much more than that.
The final form of the protests don't address the frustration of HK residents over living costs.
The British rule was more successful because it was governing at arms length. London never flexed like Beijing by actively disqualifying publicly elected legislators and meddling with its internal affairs, eroding individuals freedom and rights.
Eg pressuring companies like Cathay Pacific, Big four accounting firms to take action against employees participating in lawful assemblies and protests.
