Okto-duo 

"Okto-duo" is a piece of art by Victor Vasarely, a Hungarian-French painter and graphic artist known for his contributions to the Op art movement. This artwork consists of two octagons, one blue and one purple, each with a series of smaller octagons layered inside, creating a sense of depth and optical illusion. The use of contrasting colors and geometric forms is characteristic of Vasarely's style, playing with the viewer's perception of space and color.