It's in this thread. A few posts up states that there are a number of launcher apps that allow you to customize. I haven't delved too deeply yet but I'm sure I'll fine something. I see what you are saying though, that should be a simple task as going into "settings" and changing what you like.
It's actually not changed easily. Launcher apps don't change color schemes. You can download themes, but it wont change the color scheme on every app (music player, gallery, etc.)