PROVIDENCE — It takes one man a full day to make the massive radiator of a Rolls Royce, and another five hours to polish it. But there is a mystery in the red RR initials on this 1929 Rolls Royce Piccadilly Springfield Roadster, owned by Dick Shappy, at left, of Providence.

Why were the initials on all Rolls Royces changed from red to black after 1930? Were they changed to commemorate the death of Henry Royce, one of the founders, as most you ask will tell you? But he died in 1933.

Or was it because Royce decided that the black letters would be more aesthetically appropriate? Some customers complained that the red RR clashed with the color of their car. The Prince of Wales Edward VIII was one who was said to be particularly outspoken on the subject.

David Brownell, former editor of Hemmings Motor News, and Fred Roe, author of Duesenberg, Pursuit of Perfection, agreed the color-clash theory probably closer to the truth, but it remains a question that keeps car nuts up late at night searching for an answer.