US Patent No. 8,921,299 B2; The Procter & Gamble Company has patented a detergent composition comprising tiron (1,2-dihydroxybenzene-3,5-disulfonic acid, or mono- or di-sulfonate salts of the acid); a ligand capable of chelating to Fe3+, wherein the ligand has a binding constant for Fe3+ that is greater than 1018 M−1, and wherein the ligand is selected from the group consisting of aminocarboxylates containing at least two N atoms, aminophosphonates containing at least two N atoms, and gemin...