Disclosed are methods for obtaining blue anthocyanin pigments and compositions including such pigments. This blue anthocyanin is present at an acidic pH (where anthocyanins are most stable) and may be used as a natural color additive. The methods can include cultivating a plant callus from a plant capable of producing anthocyanin in which the callus is treated with a blue anthocyanin-generating agent at a concentration sufficient to generate callus with blue anthocyanin pigments. The method can also include recovering the blue anthocyanin pigments from the culture. In an example, the blue anthocyanin-generating agent is ammonium molybdate.
