How are you differentiating between "colonial" and "imperialistic"?

The British in India, Africa, Burma, did not settle these lands with British colonists and displace the native inhabitants. Still, these territories were generally called British Colonies, and also parts of the British Empire.

It's hard to see what the difference was between colonialism and imperialism?

The Ottomans attempted to conquer Christian Ethiopia in East Africa (and were close to succeeding when Portuguese aid unexpectedly arrived). Was this imperial expansion, colonial expansion, holy war?

The Ottomans certainly colonized the former Byzantine Empire both by "imperial conquest" and by moving in settlers. Their expansion into the Balkans could also be said to be both colonial and imperial.

Not sure if there is any difference?

I can't answer your question on Ottoman colonization/imperialism since I don't know much about the Ottomans. However, I can attempt to answer your question on Russian expansion into Siberia.

The spread of the Russian tsardom and empire into Siberia can be considered colonialism. After the Russians conquered and subjugated the various Siberian peoples, they were quick to exploit the various natural resources found in the region (such as furs, lumber, and minerals). To protect these lands from Chinese expansion and angry Siberian tribes, the Russians created forts and outposts. The Russian government ordered many Slavic peoples to settle these outposts and forts to guard against any foreign threat. Initially, it was mostly the warlike Cossacks that inhabited Siberia and protected it from foreign threats. However, many people who were considered undesirable by the Russian government were sent to Siberia to help increase the population there and to keep them far away from civilization. This included political prisoners, murderers, thieves, and rapists. These policies are very similar to that of British colonialism, who resettled Australia by sending criminals over.

The Russians also massacred many of the indigenous peoples of Siberia. Ethnic groups such as the Yakuts, Itelmens, and Chukchi were just some of the people who were slaughtered, raped, and forced to integrate within the Russian empire by colonialists. This type of behaviour is the same amongst Western empires. The British, French, and Spanish all violently destroyed the various Native American tribes of North America in order to incorporate these lands into their empires. If Russian expansion into Siberia is not considered colonialism, I don't know what is.

What Ottoman incursions are you talking about? The furthest they ever got in East Africa were a few coastal towns in today's Eritrea.

Maybe you're referring to Oman/Zanzibar's 19th century East African Empire?