2003 XJ8 brake light

If the problem is not a simple electrical problem for the brake lights, then it may be a problem with the circuit board that powers the brake lights. See this:

As for the interior color codes, use the search function in the upper right hand corner to find on this site a listing of the three letter color codes and the name they map to. With that you will have a reference to the shade needed to match what you have now.

Dave