monochrome

For an image, the term monochrome is usually taken to mean the same as black-and-white or, more likely, grayscale, but may also be used to refer to other combinations containing only tones of a single color, such as green-and-white or green-and-black. It may also refer to sepia displaying tones from light tan to dark brown or cyanotype (“blueprint”) images, and early photographic methods such as Ambrotype, Tintype and Daguerreotype, each of which may be used to produce a monochromatic image.
In computing, monochrome has two meanings:
it may mean having only one color which is either on or off,
allowing shades of that color, although the latter is more correctly known as grayscale.