Anthocyanins are responsible for an interesting variety of colors in flowers, red fruits, and plant-derived foodstuffs. Experimental evidence is presented supporting an unusual color change from red to blue during storage. It has been investigated as a function of temperature at constant pH (pH <2). The color properties of the vinylpyranoanthocyanin pigments, usually designated portisins, have been studied in this work using both experimental and theoretical techniques. The visible spectra obtained from the two approaches were in good agreement. This behavior was explained by a reversible physical-chemical change due to electronic and vibrational properties.