Coloured Scrollbars, accessibility naysayers & natural selection
I've read many an argument about why coloured scrollbars shouldn't be part of the W3C standard. By my estimates the nays are absurd.
If we must conform to such stringent accessibility standards why then have I encountered numerous pages with cyan backgrounds or worse yet fuchsia (there's a reason these colours are used in alpha masking) If we were to tote the accessibility mantra should we then strike those from the web palette? Of course not, the web is natural selection in action, in essence; if your site is an abhorrent eyesore it will be consigned to the wastelands.
Custom scrollbars can be vital to a sites aesthetic particularly when they are used on internal elements, many people cite 'the terminator paradigm' whereby they feel developers shouldn't be able to take over their browser... Judgement day is coming, malicious web developers world wide are laying in wait to spring their tie-dyed scrollbars of death upon the unsuspecting.
Elaborating, it's a contentious topic as to whether the bars should belong to the page or the browser. I doubt I need voice my allegiance to the page. We can create custom buttons, drop-down menu's, all sorts of gadgetry & html hoodoo voodoo why draw an arbitrary line in the sand when it comes to the scrollbar?
If an individual were insistent on keeping the faithful grays (in vista at any rate) for whatever reason, taste, colour blindness, poor eyesight - simply provide a browser setting to disable these customizations, accessibility need not hinder the unhindered.
To conclude I guess I ought to have better things to do with my time than blog about scrollbars but unfortunately it seems I don't.
Further reading
Google - coloured scrollbars firefox
W3C - Disabling custom scrollbars in IE