"A long-cherished wish has been fulfilled, for now for the first time it is possible to take home impressions and memories in which color plays an important role." So wrote the editor enthusiastically in 1937 in the very first full-color issue of Kleinbeeld photo magazine. Almost a hundred years after the introduction of photography, the small-screen color slide film was a huge revolution. Until World War II, history was experienced purely in black and white or in nostalgic sepia tones. Above the newly bombed Rotterdam, everyone expects dramatic clouds of smoke: not in color but in moody black and white. One of the first color photographs of a burning Rotterdam shows a house with spring blossoms in the garden. The first impression is that of a cheerful spring day. Until through the windows of an adjacent building the devastating fire becomes visible. From the period 1937 - 1945, the Rotterdam City Archive has recovered no less than three hundred extraordinary color slides. From these, a broad and diverse selection was made for Rotterdam, the very first color photographs, 1937-1945. The selection has been supplemented with the oldest known color slides by Alphons Hustinx and Hugo Jaeger. These very first color slides have both documentary and cultural-historical value and give new color and meaning to the history of Rotterdam