Crystal violet, (tris(4-(dimethylamino)phenyl)methylium chloride) 1 is a widely used acid-base indicator found across educational laboratories, in chemistry sets and commonly used as stain in biology. It is a benchstable solid that exhibits a dark green colour in the solid-state and results in a purple/blue solution when dissolved in aqueous (pH > 2) and non-aqueous media (Figure ). Between pH 0 -2, a green solution is observed and a yellow solution is observed at pH < 0 (Figure ).