How and why does Joseph Conrad in The heart of darkness use color so much? plz explain?

After hours of coercion, Pi tells a second story, a story much less fantastical, ..... from the musical Chess the theme is: 'How can I love you so much, yet make no move? .... but she does explain herself to her friend, Phoeby, with the implicit .... HEART OF DARKNESS by Joseph Conrad MAIN STREET by Sinclair Lewis