Monochrome means one colour, so in relation to art, a monochrome artwork is one that includes only one colour
For centuries artists used different shades (tones) of brown or black ink to create monochrome pictures on paper. The ink would simply be more or less diluted to achieve the required shades. Shades of grey oil paint were used to create monochrome paintings, a technique known as grisaille, from the French word gris meaning grey. In such work the play of light and dark (chiaroscuro) enabled the artist to define form and create a picture.
In the twentieth century, with the rise of abstract art many artists experimented with making monochrome painting. Among the first was Kazimir Malevich who about 1917–18 created a series of white on white paintings (see suprematism). In Britain, Ben Nicholson created a notable series of white reliefs in the mid 1930s. Monochrome painting became particularly widespread in the second half of the century with the appearance of colour field painting and minimal art. The French artist Yves Klein became so famous for his all-blue paintings that he became known as Yves the monochrome.