Perhaps it's a stupid question, but how do you enable scrollbar stylization in Firefox?

Install a theme?

Not sure if that answers your question.

you mean like the IE javascript exploit? I don't think you can do that in firefox, although like DJ said, you can install a theme

I don't want to change permanently.

I remember when I used Opera some pages had those stylized scroll bars. HHAH had a grey one. Now they all look the same. Not that it's particularly important to me, I just want to know whether there is some easy way to turn this on in Firefox.

EDIT: Compare those two:

ah yes, its a javascript exploit that overrides the colour scheme of the frame.

Its none W3 standard, and I guess the mozilla team didn't view it as necessary. You'd have to relax all the javascript rules and have a check

Already tried it, doesn't work. Ok, forget it, just thought there might be some option I couldn't find.