The pigment cyanidin aglycone is one of the anthocyanin molecules that gives red cabbage (Brassica oleracea var. capitata f. rubra) its characteristic red coloration. Many young chemists have used this “red cabbage indicator” to study acid–base chemistry. Estimate the pH range at which cyanidin aglycone shows a color change. Anth-H Anth- + H+ Ka = 1.3 x10 -7