Because of Sarah Jessica Parker's naturally curly hair - this super straight style probably took a good amount of time. But WHY? It looks like crap. When you have a long nose and long face (which many anti-SJPers might call equine), a long, one-length hairstyle like this just elongates the face. And a boring style like this just draws attention to her aging face. We can't all be 25 forever, but a great hairstyle can make you look 10 years younger - and this ain't it.
And the color? I've given up on SJP's color ever since she started doing those terrible Garnier home color commericals. While this style has highlights and lowlights (which you will never ever get from box all over color), it's so dark and uninteresting that it ages her even more.
I love you SJP, please go back to sun-kissed curly hair!