Abstract: Disclosed is an original approach to solving the environmental problem associated with the use of Cr-based metallized azo dyes to deliver black shades on natural and synthetic substrates. This invention affords methods for both the synthesis of metallized dyes and the generation of black dyeings using those dyes without employing metals designated as priority pollutants at any stage in either method. The key element of the disclosure is the use of black 1:2 Fe complexes of azo dyes in lieu of currently used Cr-based complexes which are based on environmentally unfriendly priority pollutant metals without compromising the desirable high fastness properties of the latter complexes, an accomplishment heretofore assumed unachievable.