Leafing through “Signs for Peace: An Impossible Visual Encyclopedia,” compiled by Swiss-born graphic designer Ruedi Baur and his wife, sociologist Vera Baur Kocko, the reader starts out with a feeling of optimism. The cover of the book, published by Lars Muller Publishers, and its first pages, are in hues of shining orange, pink, green and yellow. They promise a happy ending, as does the book’s title.