Gary G
3734
Based on careful inspection of the evidence...
...I suppose that my answer will have to be yellow -- although I did not spec this car myself, as is obvious from the presence of the poseur badges on the flanks 
I liked Don's answer (black) although I can't remember the last time I had a car with true black calipers -- the BMWs had plain silver ones, and even the 512 TR calipers were anthracite with silver highlights, not black...
Best,
Gary G