Well here it is. Pour yourself a drink, LOG-IN and look around. It takes a while to get used to it. Navigation is much easier. I don't consider the colors to be set in stone quite yet.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .