For the Mondiaal narratief erfgoed, I designed a series of books of six editions of the series “Verhalen van ver en lang geleden”, a series of books that each four countries cited three stories of each country in a book.
I gave each country its own color which always had to indicate on the cover in which the country is on display in the color that is reflected in the book. That gives you an overview and breakdown in each book where the stories of each country in preventing.
This idea is continued in the next series therefore when you have a single book or several books it gives a wonderful color palette that whenever you have a new book of the edition is multiplied. The return of the colors and the manner in which the specific countries in the book are indicated by a color make sure you get a set of series feelings.