In the present paper the authors are publishing the results of the genetical analysis of three color types occurring in young leaves of Coffea arabica L : green ; dark bronze and light bronze. Based on extensive data obtained from progenies, Fi and F2 hybrids and back-crosses, it is concluded that only one pair of allelomorphic genes control these colors for which the symbols Br-br are proposed : br br, the double recessive, constitutes the green type, Br br, the heterozygote, the light bronze one and Br Br, the double dominant, the dark bronze one. The dark bronze colour is therefore incompletely dominant over green, the Fi between the two being light bronze. In the group of homozygote dark bronze plants a certain variability of the maximum intensity of the bronze colour is noticed, which is most probably due to modifyers which intensify or dilute the expression of this character. Two papers, respectively by Stoffels (8) and Narasimha Swamy (7) dealing with the same subject are critically discussed.