I thought all the original cars came with Black fenders and frame? I would assume anyone painting a car would paint the frame running boards and fenders the same color. For example if you are painting the fenders the same color as the car, you would paint the frame and running boards the same color as the car. If the fenders are a contrasting color to the body, the frame and fenders would be the same color. If you matched the frame to the body, you need to remember that the frame is also visible in the wheel wells. I would find a black and white photo, print it out and color it in to see how the different combinations look.