Thats true, but now we are going back to ancient history. I would consider that more as Mediterranean colonization rather than European colonization. For the last millenium at least (discounting the small byzantine empire), turkey has not been colonized.
These definitions all get kind of fuzzy. Afghanistan wasn't "colonized" but Britain exerted a significant amount of control, as did the Soviet Union, at different times. China was defeated and forced to accede to foreign concessions. It wasn't under a colonial administration but many of its laws were being dictated by Europeans. Bhutan was absolutely subordinate to Britain and although it didn't officially join British India, it was effectively controlled through the same channels.
You are right about Afghanistan, but my research on Bhutan is that Britain only had control of their foreign relations and had little control over the country. .
You're right, this is where the definitions do get fuzzy. To define it here; colonization is "the action or process of settling among and establishing control over the indigenous people of an area." The establishing control is fuzzy, but the settling among is not. British people went to India, but not to Afghanistan (at least, not in significant amounts) and that is the important distinction. The same applies to Bhutan. With China, it wasn't under colonial administration, which separates it from other like India which were (in addition to the point above).