I don’t think Japanese or South Koreans view the country as colonized, even though a foreign country controls their military. And for South Korea, a foreign country dictates whether South Korea can officially end the war with the north.

But some Japanese companies did stop working with Israel following the ICJ findings.

Given Korea's own history of getting colonized, I honestly have to wonder where public opinion on Palestine stands in the south.

Vietnam and Palestine are almost a parallel image, but the former is still cooperating with Israel. So being colonized is not always a great indicator of anything