You can just press Ctrl+k and a small thing will open up. Just select the colour there. Then type what ever text you may need. When you want to change the colour do the same thing again.
If you want to make some text bold then just press ctrl+b.
Alternately you can just press ctrl+r and a small thing will open up. Just select what you want to do (bold, italics, underline and strikeout are the available options)
So you see, it is far easier to use this codes than to remember the codes for every colour.
This method is only applicable in the IM windows (ie chat windows) and obviously needs Messenger Plus! to work
You can change your nickname in the IM (chat) window by typing
/nick {Your nickname here with all the codes that you want to use}
/ 
