Coloured scroll bars still have their place, especially when using iframes.

You gotta remember that IE is still the main player as far as browsers go, 67% compared to mozilla's 27%

Firefox browser use is also the domain of the internet savvy, not the regular Joe Surfer. Therefore it is still recommended to design for IE and scroll bars are one of it's features.

I have not designed them into any sites lately but have helped two younger designers weave them into their static image pages with absolute positioned iframes. The scroll bars were blended into the pages imagery and made the page look seamless.