To use colour in your name: open a conversation window, type /nick and a space then press CTRL+K. Click the colour you want, type your name and press enter. If you want to use multiple colours, just use CTRL+K in your name multiple times, right before where you want the colour to show up.
To change your contacts name into a coloured one:
rightclick the name in contactlist, plus extras > rename contact
give your contact a custom name or just put (!N), hightlight it
ctrl+k, choose color
<enter>
(!N) displays the name as your contact has set it.
You can also give them a customname and show the name how they set it.
To do that rename em: <customname> - (!N), you can colour whatever part you want by highlighting, pressing ctrl+k and choosing colour.
Make sure you have customnames enabled:
Plus > preferences > contactlist >customnames (tab)...check atleast the first box (the second one is to show the name you gave in conversationwindows aswell).
Edit: YW