The definitions are blurred, so you aren't entirely wrong in calling it a form of colonialism, but there were not particularly massive waves of Turkish settlers outside of Turkey, and non-Turkish citizens of the Ottoman Empire were relatively advanced compared to inhabitants of colonies in Africa and the Americas. The Greeks, Mamluks (Egyptians), Hungarians, etc. were far more 'civilized' than tribes in colonies in Siberia, Australia, Canada, and elsewhere. Most people would not call the non-Turkish Ottoman territories 'colonies'. The important divide which this creates is that the Ottomans must acknowledge the various groups in their empire and make sure provisions are made to limit their unrest. The best-known example of this policy of tolerance is the millet system, which gave extra autonomy to Ottoman Christian and Jewish minorities. This is the exact opposite of policies enforced in most colonies, which advocated deportation and massacre of the native populace. The most infamous example of this is the Trail of Tears, which Andrew Jackson directly defied the U.S. Supreme Court to carry out. The Ottomans carried out their fair share of killing their own people (Armenian Genocide) but were still more tolerant overall of these minorities than other European nations...

...except the Austro-Hungarian Empire. Similar to the Turks, the Austrians ran as tolerant a society as they could, because they were only a minority with Hungarians, Croats, Slovaks and more desiring autonomy. The Austro-Hungarian Empire is the closest analogue we have to the Ottoman Empire; these two, and nations like them, inhabit a category known as "multinational empires". Most other nations - even (and especially) those which were once colonies themselves - have their treatment of the indigenous populace marked by Indian Removal Acts, Conquests of the Desert, and deportations to Siberia.

Edits for grammar.