In a process for reducing the visible color of a crude aromatic dicarboxylic acid containing colored contaminants, an aqueous ammonia solution of the crude aromatic dicarboxylic acid is prepared and contacted with hydrogen in a reactor in the presence of a heterogeneous metal-containing catalyst that includes a noble metal and a support. The process is carried out under conditions of temperature, pressure, and contact time effective to reduce the visible color of the aromatic dicarboxylic acid.