Vasarely Quadrilaterals

Inspired by a Vasarely piece of op art shared by Maria Linares Freire. Michael Borcherds helped me with the coloring idea, tracing a polygon instead of coloring a list. The Vasarely button moves the quadrilaterals to close to the pattern that he used, but you may move the starting and ending vertices to where you would like. What do the sliders k and p do to the color?