Colonialism and Ethnocentricism in Heart of Darkness

There are many things that happen within the book, Heart of Darkness, that are either blatantly racist or in many ways heartless. A lot of scenes lend themselves to hinting at the idealized western culture and how the people in the jungle are 'untamed' or animal-like. There is also a strong sense of the need for colonization and to 'improve' this culture. What are some ways that Conrad makes this evident in his book? And do you think that he himself believes this is right or is it him trying to make known an issue in our society?