Ok I have found a bug involving the colours and emoticons.
If you press ctrl-k (for the colour box) then press comma and input an emoticon starting in a number, eg the eye rolling emoticon,
[code 8 -)], the whole display of the chat window goes the colour of the number at the start of the emoticon (in this case yellow) and it only goes back to normal if the chat window is reopened. It even works if you set your own custom emoticons to begin with a number.
I hope this report meakes sense. If not just say and I'll try and make it clearer.