IRCCloud replace & with formatting characters | &b is bold, &r is reset, &<number from 0 to 15> is a color | I'm going to regret this.

irccloud-colorize.js

var inputbox = $('#bufferInputView' + cb().bid());
var msg = inputbox.val();
inputbox.val("");
var cc = "\u0003";
var bold = "\u0002";
var reset = "\u000f";
var italic = "\u0016";
var underline = "\u001f";
cb().say(msg.replace(/&b/g,bold).replace(/&r/g,reset).replace(/&i/g,italic).replace(/&u/g,underline).replace(/&/g,cc));