That the conflicts are well-known and have been happening for a while is quite true of course.
But this bizarre framing of these conflicts as "between Russia and colonialist powers" (as if Russia was not also a colonial power, or its influence games in Africa were any different from those of the Western powers) is just propaganda, and rather trite propaganda at that.
But indeed it was, and this is an extremely basic fact of its history. It wasn't run on exactly the same model as the overseas empires of the Western European states, but its modus operandi absolutely fits the definition of a "colonial empire" per the definition in Wikipedia:
A colonial empire is a collective of territories (often called colonies), either contiguous with the imperial center or located overseas, settled by the population of a certain state and governed by that state.
This idea that conquest can't be called a "colony" (or that territorial contiguity has anything to do with the definition of the term) is just silly. As if the American States didn't promptly set out to settle and colonize the West after 1789 (because these places were contiguous to it), or Germany didn't very explicitly set out to colonize Poland in 1939, and so on.
Russia is also providing economic and political support to many African governments, especially those who have turned away from the west and are afraid of regime-change operations.