Less than 100 years ago, monochrome capture was a limitation, not a choice. The advent of digital and mobile photography has rendered black and white, or grayscale, images an artistic choice. Surely such images have a dramatic effect, yet there is more to black and white images than just changing an option on the capturing device (be it a digital camera or a phone).
Our understanding of colors and formal color models predates color images. Thomas Young, in 1802, postulated the presence of three types of photoreceptors or cone cells (as shown in the following image). His theory detailed how each one these three cone cells are sensitive to only a particular range of visible light. The theory was further developed to classify these cone cells into short, middle, and long, preferring or blue, green, and red, respectively: