I am at present sponsoring this little beauty via Raise’n Rescue. He is called Dassie and has a so-called fever coat. Fever coats occur when the mother had a fever or was stressed during pregnancy. Due to this, the pigments have not been fully deposited into the fur. The extremities of a fever coat are usually darker because their temperature is cooler. Here is Dassie with his mother and siblings. As you can see, all the kittens have fever coats.
This grey fur falls out and is replaced by the natural colour as the kittens (which are usually perfectly healthy) grow. So these little grey kittens could be pitch black, little tuxedos, or perhaps tortoiseshell.
Below is Dassie, my foster sponsor. Isn’t he gorgeous?