The division between color and black and white in photography has been overemphasized based on the limitations of 20th century processes. 21st century processes are significantly different and beg a reconsideration of this division. Today, when we make black and white images we typically capture, process, and print with color.
When people use the term black and white they generally mean neutral (without saturation or bias towards one or more hues). Typically the use of the phrase “black and white” also encompasses warm and cold toned monochromatic images, cross-toned duochromatic images, and in some cases subtly tinted polychromatic images. The guiding principle behind these related but varied palettes is an emphasis on luminosity values, along with a restrained use of hue and very low levels of saturation.