Use the up arrow key to set the height by putting your mouse the distance from the black circle the amount you want the height to be. Do the same by pressing the down arrow key for the width and then press the mouse where you want the center of the circle to generate. If you use the color slider, you can change the color of the next circle. When you are done drawing, you can press g to save your creation and then press g again to reload your creation. However, right now, this wipes all colors. Make sure to turn on turbo mode.
This started as just an experiment, but it is now a full project!