Shoutbox

Hi, i have a little bit of knowledge in javascript and such and I'm just wondering if it would be possible to have an add on that can change the font colour of certain characters. So for instance every time I type a "e" it would be in an orange font where as all the other letters would be my normal blue.

I think it would be cool if like all the numbers and symbols were in the different colour and that by editing the script i could add/remove what characters are in the different colour and what the hexcode of the colour is.

I've searched round the forum a bit and there doesn't seem to be much on this and I'm just wondering if its possible? Thankyou for your time.