Generalization of acid and bases using red and blue litmus paper?

Litmus paper is a simple indicator used to determine whether a substance is acidic or basic. Red litmus paper turns blue in the presence of a base, while blue litmus paper turns red in the presence of an acid. This color change occurs due to the pH-sensitive dyes in the paper reacting to the hydrogen ion concentration in the solution. Thus, litmus paper provides a quick visual representation of a substance's acidity or basicity.