In short, the Company may appear to be "white" and pure, but it is actually quite the opposite, as denoted by the accountant and his white shirt.
Some critics have claimed that Conrad's use of "darkness" to represent evil suggests the racist assumptions of the novel; others argue that the "white" characters in the book are actually more "black" than the natives they slaughter and that Conrad's imagery stresses the hypocrisy of the Company and its "white" employees. Regardless of this critical dispute, a reader should note that Conrad toys with white and black imagery throughout the course of the novel, and of course, in its very title.
Marlow feels like "an imposter" when he leaves the Company's headquarters, because he has joined the ranks of an outfit whose assumptions about Africa and European activity there sharply contrast with his own. Marlow has no imperialistic impulses and only seeks adventure — but he is beginning to see the Company for what it truly is. Thus, Marlow's growing perception of the moral decay around him becomes one of the major issues of the novel.
Like the Company headquarters, Africa itself is initially portrayed as an enchanting and intriguing place. The continent is described as unfinished and "still in the making," possessing an air that beguiles Europeans to "Come and find out" if they can survive there.
This portrayal of Africa as an untouched paradise, however, is quickly countered by Marlow's description. He notices a French man-of-war firing its guns into the bush; the "pop" made by its guns highlights the Company's ineffectual attempts to subdue the continent. Similarly, Marlow notices a boiler lying in the grass, an unused railway car resembling "the carcass of some animal," a series of explosions that do nothing to change the rock they are attempting to remove, an "artificial hole" the purpose of which he cannot discern, and a ravine filled with broken drainage pipes. Stunned by these images of chaos, Marlow remarks, "The work was going on. The work!" Clearly, these signs of waste and ineptitude are not what Marlow expected to see upon his arrival; these discarded machines symbolize the complete disregard of the Company for making any real progress in the Congo, as well as the disorganization that marks its day-to-day operations.
