One common indicator used to detect bases is with litmus paper. Red litmus paper changes its color to blue when it comes into contact with a base. Phenolphthalein is another indicator that turns fuschia color in the presence of a base. A third indicator is red cabbage juice. The color of the cabbage indicator changes to green or yellow in the presence of a base. It is important to note certain indicators are not specifically made to identify bases, but instead provide an approximate indication of the pH of a solution.