If you want to give an example of successful Westernization, Japan is a terrible example.

In the 17th century, the Dutch broke the commercial monopoly the Portuguese had over Japan, and the infighting between Dutch and Portuguese bothered the Japanese so much that they closed off the country. Only the Dutch (who had the wisdom to never use missionaries) were allowed to keep trading, and only through one port in one island.

Fast forward to Commodore Perry and his gunboat diplomacy. Panicked, the Japanese quickly copied the ways of the West, including the industrial revolution and the German education system, and by the next century they had become an imperialistic oppressor over much of East Asia. It took WW2 to put a stop to that. Then the Americans took charge of ruling the country until it didn't appear to be a threat anymore.

During the 1980's it seemed Japan was headed for big things, but they didn't know what to do with that promise. Maybe they panicked again. Now Japan is a toothless beast, unsure of its future, economically uncertain (still the world's 3rd, but stagnant), and demographically doomed.

I was tempted to give Siam as a successful example instead, if only because they managed to never be colonized, but right now they're such a political joke that my first impression on this matter stands: there's no way colonization can end well.