The article by Szilard Pesek and Radu Silaghi-Dumitrescu explores the nature of the blue color observed in the iodine-starch reaction, specifically focusing on the iodine-iodide-starch complex. The authors review the extensive literature on this topic, highlighting three main sources of charge transfer: chains of neutral I2 molecules, chains of poly-iodine anions, and mixtures of I2 molecules and iodide or polyiodide anions. Recent data suggest that the best candidate for the "blue complex" is an I2-I5−I2 unit, which is expected to occur repeatedly within the amylose helix. The article also discusses the structural details of the complex, including the role of the solvent and the geometrical data obtained from various spectroscopic techniques. The authors conclude that the most recent data support the hypothesis of a repetitive I2-I5−I2 unit as the primary structure responsible for the blue color in the iodine-starch complex.The article by Szilard Pesek and Radu Silaghi-Dumitrescu explores the nature of the blue color observed in the iodine-starch reaction, specifically focusing on the iodine-iodide-starch complex. The authors review the extensive literature on this topic, highlighting three main sources of charge transfer: chains of neutral I2 molecules, chains of poly-iodine anions, and mixtures of I2 molecules and iodide or polyiodide anions. Recent data suggest that the best candidate for the "blue complex" is an I2-I5−I2 unit, which is expected to occur repeatedly within the amylose helix. The article also discusses the structural details of the complex, including the role of the solvent and the geometrical data obtained from various spectroscopic techniques. The authors conclude that the most recent data support the hypothesis of a repetitive I2-I5−I2 unit as the primary structure responsible for the blue color in the iodine-starch complex.