Who does "Heart of Darkness" portray as the "savages"?

In Heart of Darkness, a constant repetition of the word savage, showing us that Conrad, the author is trying to expose us to and consequently, critically think about what truly constitutes a savage and how western society takes form of this savagery. In the beginning Marlow starts the book by alluding to the conquests of the Romans, naming the "uncivilized" territory as "Sandbanks, marshes, forests, savages,—precious little to eat fit for a civilized man" describing the way in which the Romans alienate the culture of the "savages" that they must conquer and civilize. Conrad continues this characterization of the savages when he writes, "march through the woods, and in some inland post feel the savagery, the utter savagery, had closed round him,—all that mysterious life of the wilderness that stirs in the forest, in the jungles, in the hearts of wild men." This shows the “savagery” that is perceived from the civilized world when looking upon the uncivilized world.  This savagery could most simply be defined as the allowance of letting the most primal and basic human instincts shine through.  This savagery, is then paralleled with the European populace whose society is basically equated to a "whited sepulcher".  This illustration shows how the western society knows and can clearly tell the underlying destruction that the society causes in order to maintain its way of life, however, this process is painted over and forgotten about in an attempt to distance the society from the harsh workings that have been conspired by civilization in order to maintain this high quality of life.  This harsh process is the colonization of the "savages" down in the Congo, leading us to the point where it can be inferred that the Africans who follow their traditions and primal instincts are not savages, but rather that the colonial force who knows full well the terror that is brought by its imperialism and continues to justify it through the means of helping the poor folks become civilized is the real savage.