Certainly you can compare Russian expansion to European colonialism. However, there are many features of European colonialism that distinguish it from Russia's expansion into Siberia: the relationship between the colonizer and colonized more closely resembles settler colonialism than a strictly extractive, subjugated relationship (consider the Circassian genocide); the social structure of Russia was vastly different than Europe in the 19th century (remember that serfs were not freed until 1861); and the expansion to Siberia was undertaken over land, rather than by sea.

That being said, Russian expansion does share similarities to traditional European colonialism (Russification). This is a very broad question covering quite a long time range (and I would certainly look at how the Soviet Union expanded!), so it would be hard to cover in an answer here, but I am happy to recommend a few books.

Russia's Orient: Imperial Borderlands and Peoples, 1700-1917, Russia’s Steppe Frontier: The Making of a Colonial Empire, 1500-1800, and Internal Colonization: Russia’s Imperial Experience are all good books exploring this question. I am particularly fond of Internal Colonization, but Russia's Steppe Frontier is probably the best introductory text.

There is a lot to say here, but I will link to an answer I wrote on this topic that would indicate that yes, not only are there strong parallels between Russian imperial expansion into the Caucasus, Central Asia and Siberia to European colonialism, but often members of the Russian elite and government explicitly made that comparison.

Whether the Soviet period treatment of nationalities qualifies as colonialism/imperialism is actually something debated among historians of Soviet nationality policy - I'll leave that for now for another one of our experts to delve into if they have the time.