What color is St. James's white horse?

[Bapopik at AOL.COM]

   "What color is St. James's white horse?"
   (ANSWER:  White.)

   The Santiago tour guide today said that this proverb/maxim/saying is from the 17th century figure of St. James on a white horse in the Cathedral of Santiago de Compostela.
   I don't have my phrase books here with me.
   I do know that the phrase took on a life of its own in the U.S., becoming "What color is my blue car?" and the like.

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MISC.

   The Santiago cathedral is also known for its famous Rod of Jesse (but it looked nothing like Sheidlower to me).  You put your hand on it and make a wish.  I think the OED works this way.
   "If it ain't baroque, don't fix it" is not original to my tourist party--the tourist/comedian in my group said he heard it from Disney's version of ALICE IN WONDERLAND about six years ago.  I don't have my search engines to check.
   The best book on Spanish cooking appears to be COOKING IN SPAIN (1996) by Janet Mendel.  It's 370 pages, with a SPanish/English glossary on pages 337-343.
   My tour guide just ate a pastry called "ear," but it contained no elephants.