Color bars are standardized test patterns used in television and video production to ensure accurate color reproduction. They consist of a series of colored vertical bars, each representing a specific color and intensity. Color bars help technicians calibrate monitors and cameras, ensuring that the colors displayed are true to life. In broadcasting, color bars are often displayed at the beginning or end of a transmission, serving as a reference for viewers and technicians alike. They are essential for maintaining consistency in color quality across different devices, such as televisions, monitors, and projectors.