Many folders have custom icons -- e.g., at the root level, Applications, Developer, Library, System, Users, and at the user level, Desktop, Document, Downloads, Library, Movies, Music, Pictures, Public, Sites. In Tiger, the folders had colorful icons with light blue, semi-transparent background. In Leopard, however, the folders are darker blue, and the icons are blue too. Blue on blue! This makes the folders much harder to distinguish. Nobody in the world outside of Apple likes this change or understands why it was done.