CSS font colour question

[Butters]

Just looking at Robs post about CSS hack for OcUK forums on Firefox and something caught my eye which I'd like to know the answer to.

Why in CSS do you use font color: #fff;

Instead of font color: #fffff;

?

 

[Butters]

OK, but I take it it can only be short hand for colours that have the full compliment i.e. #ffffff and #000000 and #222222 if you have #f5a2c6 you would need to add all of it?