I found this at www.hoofprints.com

The Little Book of Horse Poop by Becki Bell
So useful, so interesting, so misunderstood. Only a true horseperson can appreciate the lowly manure pile. This collection of trivia, tips and tributes will teach you everything you had no idea you ever wanted to know about your horse's manure. - Hardcover 5" x 5", 91 pages

"The carriage horses employed for the wedding of Prince Charles & Lady Diana were fed pastel colored dyes so their manure would match the wedding's color scheme."

Does anyone remember what the wedding colors were???