This refers to the color of the display in tube-based image intensifiers.

Green phosphor is the traditional choice and the most common. The human eye has evolved to be most sensitive to green-yellow wavelengths (around 555nm), and green phosphor was historically the only option. Most military and commercial tube-based devices use green phosphor.

White phosphor produces a black-and-white image instead of green. Proponents argue it is easier to interpret detail and contrast in white phosphor, particularly for edge detection and facial recognition. Studies within military communities have generally supported white phosphor for observation tasks, though green phosphor remains dominant in military fielding due to legacy training and logistics.

For civilian use, white phosphor is increasingly available in premium devices and is considered by many users to provide a more natural, film-like image. The performance difference in low light is negligible; the difference is primarily perceptual and task-dependent.