jQuery: animate text color for input field?

I've got this really simple piece of code that I thought was the correct way to get jQuery to animate the text color for a given input field.

$('input').animate({color: '#f00'}, 500); 

But it won't work. However, I can change the text color:

$('input').css('color', '#f00'); 

I've tried this in both Safari 4 and Firefox 3.5 with the same (lacking) results. I'd really appreciate any input on this problem as I'm running out of hair... Thanks.