How to use coloured chat

Coloured chat is available to everyone with a purchasable, permanent rank. If you have a stone rank, either with or without a Plus subscription, you will not be able to use coloured chat.

In order to colour your message, you will have to put & and a number between 0 and 9 or a letter between a and f in front of your message. Every combination has one colour attached to it.

Some examples
&cGood luck and have fun everyone!
Good luck and have fun everyone!

GG - &2Well played!
GG - Well played!

&cR &6a &ei &an &3b &5o &dw
R a i n b o w

You can give colour to your messages in regular, global, team, friend and party chat. Private messages (using /msg and similar) can not be coloured.
Adding functions
Adding functions will make your message even cooler. There are five ways to flourish your messages: bold, underlined, italic, strikethrough and obfuscated. To add functions to your message, put & and k, l, m, n or o in front of your message. Once again, every combination has one function attached to it.

You can use &r to reset all colours and functions, making it plain white.

You can also combine colours and functions! To do this, you will first have to define your colour, then your functions. This is because colour definitions reset all preceding functions.