<animateColor>

What does <animateColor> give us that <animate> doesn't? I can't tell if the 
spec requires it, but all browsers seem to allow <animate 
attributeName="fill" values="purple;plum;papayawhip"  ...etc...> just fine. 
Is it just out of the kind hearts of the browsers that this works or does 
the spec require it?

thanks in advance,
David