Hello. Recently on Custom game roster we have seen people with colored names. I can tell you why this is bad. First of all it ruins the idea of creating an account since these people can be invisible. This happens not only on lobby before you start a game but also in chat channels.
So why this is bad you say? Well these people can whisper you but you can’t whisper back to them. If they decide to flood you with massive whispers and insult you. You cannot squelch them in the chat channels. I’m not sure if the command "/o igw " works on them. Its best to keep the game clean from trolls that use some tricks to make them invisible.