You don't see the difference in your nickname itself; you will see the difference in a conversation window...
<CTRL+O> is called an IRC-style shortcut (because they are also used in many IRC applications, like mIRC) which you can use to reset all the formatting tags that you've used in text and/or nicknames.
------------
You can use keyboard shortcuts to make something
bold (using <CTRL+B>), something
italic (using <CTRL+I>), something
underlined (using <CTRL+U>)...
A special shortcut is <CTRL+K>, with that you can make colors. And it is that which you use in the nick command to make colors. eg:
/nick this is black and <CTRL+K>4this is red
When you enter that command (don't enter <CTRL+K> of course, that's a key stroke you need todo
), Messsenger Plus! will change your nick to "
this is black and this is red".
But it automatically puts a "<CTRL+O>"-code (or format reset code) behind it so that every text following the nick is back to normal. So in a conversation it will look like:
this is black and this is red says:
When you use the "/nick2" command it will not automatically put the "<CTRL+O>"-code behind your nick and in a conversation it then will look like:
this is black and this is red says:
This means you can actually color the "says:" when you use the /nick2 command like so:
/nick2 this is black and and the says is blue<CTRL+K>12
will result in:
this is black and and the says is blue says:
For more info on the shortcuts:
http://old.msgplus.net/help_tutorials.php?tut=multi-format (last paragraph)
also see:
http://old.msgplus.net/help_tutorials.php?tut=multi-format-colors
I also suggest to read:
http://old.msgplus.net/help_tutorials.php
http://old.msgplus.net/help_faq.php
http://old.msgplus.net/help_cmdtag.php
/ 
