scrollbar help!

Hi all-

First I wanted to say a huge THANKS for the tutorials (whoevers responsible for them) - I found them really easy to use.

However I'd really like to know if there's a way to change the colours of the scrollbar of the browser like you can with other styles using overrides.

I'm presuming there would be some code to put in the layer...can anyone help me out here?

Thanks so much!