In this experiment we call the paint event and establish a device context to draw a rectangle and fill it with the color set by the brush. Actually, we will draw 99 random sized and random colored rectangles with a small time delay. Don't worry, it will be faster than the "99 bottles of beer on the wall" song!
This kind of frivolity can be expanded to lines, polygons, dots and circles. Something my little nephew Carlos Vegaseat enjoys watching!