Macao to Portugal, Hongkong to Britain, only these two areas can be defined being colonised by foreign countries. Because one of the most distinct effects of colonization is the official language, as both two places consider Portuguese and English as their official language respectively. And that is also the reason that Taiwan does not fit in this category even they had been ruled by Japanese for long decades.
but the mainland was never colonized by foreign forces, but military conquests and lootings by foreign forces were evidently large````
Lots people's perception of Mongol conquest of China = colonization of China is a total false.
firstly, Mongolia was not recognized by former Chinese government of ROC, it is part of China
secondly, the Chinese Yuan dynasty was founded by Mongol, and its legal system, official language, governing structure, art, literature, economy and culture was still Chinese, these share no similarities to the likes of what would have happend to the colonized.
lastly, just like Manchu emperors, mongol emperors they all considered themselves were legitimate divine successors of the Middle-Kingdom ruling legacy, and the true kins of the heavenly decendents