A bookmarklet for my wife

Just a few minutes ago my wife complained about websites with white text on a black background. For her I made this simple grey-on-white bookmarklet which sets all backgrounds to #f5f5f5 and all colors to #666. The background of the body is set to #ebebeb to preserve some of the shapes of the original site (the real reason is I wanted to use #f5f5f5, a key I used a lot when I had a windows PC and #ebebeb, the initials of a good friend).

Here’s the code. As always, suggestions are welcome.
javascript:(function(){
var%20a=document.getElementsByTagName('*');
l=a.length;
while(l--){ a[l].style.color='#666';a[l].style.background='#f5f5f5';}
document.getElementsByTagName('body')[0].style.background='#ebebeb';
})();