A minimum spanning tree of the canvas is generated using randomized depth-first traversal. Hue encodes Manhattan distance from the start. (This is not an optimal visual encoding, but it suffices and is pretty.)
Randomized depth-first traversal can also be used to generate mazes. See a maze generated with randomized depth-first traversal flooded with color, and compare color floods of spanning trees generated by Prim’s algorithm, Wilson’s algorithm and random traversal.