What are blues used for backstage?

Blues, particularly in theatrical lighting, refer to a specific type of blue lighting used backstage. These lights serve a practical function, providing illumination for crew members as they work during scene transitions or while preparing for performance elements without disrupting the audience. Maintaining visibility is crucial for safety and efficiency, especially when the stage is dark during a blackout. Thus, using blues as working lights that stay on during these periods ensures that backstage activities can continue smoothly without distracting from the performance in the front of the house.

The other options, while relevant to various aspects of theatre production, do not accurately describe the primary function of blues in a backstage context. Creating atmosphere is typically achieved with various colored lights during performances rather than backstage. Signaling actors usually involves more direct forms of communication, like verbal cues or specific signals rather than relying on backstage lighting, and while a positive atmosphere is important, it is not the primary purpose of blues used backstage.