Aha! It's the color of the book! :-)
I thought maybe it was similar to the Blue Book for Cars in that it listed
the ancestries of the variant spellings of Kusters!
I thought maybe I had missed something during my 17 years as a member and 7
years as membership chairman and 5 years as a Librarian!
Jo
The book The Descendants of Paulus and Gertrude Kusters, The First Four
Generations, published 1991 by The Castor Association of America.