Series Acro Iris, 1937

Group of 94 color postcards by Luis Márquez, published in 1937 by Eugenio Fischgrund.  Of the original 96 numbered postcards in this Arco Iris series, this collection lacks number 55 (Santo Domingo, Oaxaca) and number 82 (Governors Palace, Monterrey). 

In the mid-1930s Márquez colorized his dramatic photographs into postcards that lie between two major periods in Mexican postcard making:  black and white real photos and color chromes.  Before color film was readily available in Mexico, Márquez' technique made his postcard images appear as if they had been shot in color.  (Although Kodachrome slide film was introduced in 1935, Agfacolor print film in 1936, and Kodacolor in 1942, Mexican postcards do not reflect the common use of color film until the 1950s.) 

Source: Luis Márquez: Mexican Folklore & History in 20th Century Art Postcards. https://susanfrost.org/postcards-of-luis-marquez