You must first of all have messenger plus! installed. Then open up a chat window and just type "/nick " (without the quotes). Then press ctrl+k and a small colour pad will open up. Select the colour you want and type the screen name that you want.
You can add as many colours you may want. Just press enter and your screen name will be coloured
Eg:
/nick (ctrl+k)(select colour) (Insert Name here)
Thats the basic format. Note that there[b]Must be a black space after the word /nick