Abstract: Composition having a blue color including a buffer, an anthocyanin, and a divalent ion source. The composition may comprise an anthocyanin and a divalent ion source, wherein the average variation of ?E*ab of the composition is less than 30% of the average variation of ?E*ab of a control composition after exposure of the composition and the control composition to a 400 to 765 W/m2 light source for a period of time. The composition may comprise an anthocyanin and a divalent ion source, wherein the composition exhibits a less than 20% change in the area beneath the reflectance colorimeter spectral curve of the composition from 430 nm to 530 nm measured over a period of time. In another aspect, a method of stabilizing a blue colorant is provided. The method may comprise combining a buffer, an anthocyanin, and a divalent ion source.

Abstract: A method of producing a modified pigment by sulfonating a pigment and subsequently oxidizing the pigment. The modified pigment may have sulfonic acid and carboxyl surface modifying groups attached to the surface of the pigment. Charge balancing counterions such as alkali metals, alkaline earth metals and NR1R2R3H+, where R1, R2 and R3 are independently H or C1-C5 alkyl groups, may be associated with the surface modifying groups. The modified pigment is combined with water to produce a dispersion that can be used in such applications as coatings, paints, papers, adhesives, latexes, toners, textiles, fibers, plastics and inks.