To replace the blue banknotes of the nineteenth that no longer offer the security guarantees necessary for traffic, the Bank of Algeria launches the first issue of a series of two-color and three-color banknotes: first a 20 francs Type 1912 (Pick: # 78) printed in blue and purple on the front and green and blue on the back. A 50 francs Violet Type 1912 (Pick: # 79) is then printed in purple and blue, then a 50 francs Green Type 1912 (Pick: # 80) identical to the previous note, but printed this time in green, orange and blue. The first polychrome banknote is created in early 1921. It is a 100 francs Purple Type 1920 (Pick: # 81). The issues continue with a 5 francs Type 1924 (Pick: # 77), a 500 francs Type 1926 (Pick: # 82), a 1000 francs Type 1926 (Pick: # 83), a 50 francs Native couple Type 1938 (Pick: # 84), a 100 francs Type 1938 (Pick: # 85), a 1000 francs Farm family Type 1940 (Pick: # 86) and a 5000 francs Type 1942 (Pick: # 90).