If acid is produced in Litmus Milk, what color change occurs?

When acid is produced in Litmus Milk, it results in a color change to pink. This is due to the pH indicator litmus present in the medium. Litmus changes color in response to pH variations; when the pH of the medium drops (becoming more acidic), the litmus turns from its neutral purple to pink. This reaction indicates that fermentation is occurring, typically as a result of lactic acid production by certain bacteria. This color change is an important visual cue for microbiologists to assess the metabolic activities of microorganisms in the Litmus Milk medium.