Roger Fry, in full Roger Eliot Fry, (born December 14, 1866, London, England—died September 9, 1934, London), English art critic and artist, best known as the champion of the movement he termed Post-Impressionism. Fry was born into a Quaker family and was educated at the University of Cambridge for a career in science.
I believe the answer is Monochromatic
A color scheme could be categorized as monochromatic if it's derives only from single based hue using additional tints, tones, and shades.
The usage of these will alter the brightness and the saturation of the color just like what we see in the painting.
