Can anyone tell me if the xk/xkr black body colour is all the same paintcode or if there are more than one shade ? Thanks

 

Midnight which was on the early XK's up until mid 2008 was PEF. That was replaced by Ultimate Black which is PEL.

There is also Ebony Black which is PEC and was a non metallic colour plus Celestial Black which is PEJ and Black Amethyst which is PVS.

 

There's a very helpful resource at GTCarlot.com that lists all XK model years and available colors with pictures. Here it is:
Jaguar XK Colors | GTCarLot.com - Car Color Galleries