What colour should the safe light be in a dark room?

• A. Red
• B. Amber
• C. Dependent on specific film type
• D. Green

Answer: (C)

Safelight color must match the film’s spectral sensitivity. The emulsion can be fogged if the safelight emits wavelengths that the film is sensitive to, so the safe color isn’t universal. Different films have different sensitivity ranges, which is why you must choose the safelight based on the specific film type and follow the manufacturer’s guidance. In practice, consult the film’s data sheet to pick a safelight filter that lies outside that film’s sensitivity, ensuring you don’t expose the emulsion while handling or loading it. Some films tolerate certain safelight colors, while others would fog under those same wavelengths, so the key idea is matching the safelight to the film.