This is what I've been told. I would expect that the other aircraft that have been reconfigured with flat beds might have similar lights, for example the 767-400s, 747s, and redone 767-300s, but I haven't observed the lights on those aircraft.

If the OP really means (domestic) FC seats, I think I've seen some amber lights in the middle of the outside of the metal plate below the aisle armrest. These light up with the escape path lighting, so they're some sort of emergency lights. There are also lights that indicate that someone in the row has used the FA call button, but that little light is usually overhead, on the aisle side of the controls for lights, in aircraft that don't have the light and call button functions in the armrest.