Bridget Riley is a leading British painter who is known for her significant role within the development of Op Art, an artistic movement that concentrates on the potential of two-dimensional paintings to produce illusions of speed and vibration. While she first started to paint in black and white to generate sensations of movements, Riley later started to employ color to investigate the complex effects that combinations of discrete hues could engender in human vision.

RBYT Darker Green and Lilac is one such example, in which Riley uses minute lines of varying watercolor stripes on a gridded paper to demonstrate the subtle variations in colors that arise when they are placed next to each other. Although the same key colors of yellow, white, green, red, and teal are used throughout the painting, none of the colors appears the same as our eyes perceive them differently when they are juxtaposed against different shades. As such, Riley expands artistic foray into the layered relationships between colors and human vision, as developed by her historical predecessors like Josef Albers (1888 – 1976).