change elements' css immediately on scroll event

[crzyvirus]

I want to change the background color of in-viewport elements (using \[code\]overflow: scroll\[/code\])So here was my first attempt:http://jsfiddle.net/2YeZG/As you see, there is a brief flicker of the previous color before the new color is painted. Others have http://stackoverflow.com/questions/8966971/javascript-event-before-scroll-redrawWhat am I doing wrong here?