You draw the red zone by placing the "A" CB on the table and drawing the shape you want. Then you open tools and click the "Line Mode" icon (near the side pocket) until it shades in the shape. To get rid of the "A" CB, you press "CTRL" while left-clicking the "A" CB.
You can do the same with the "B" CB but it will be a different color. In fact, you can do it with any ball you want to get any color you want (even black from the 8B).
You can do the same with the "B" CB but it will be a different color. In fact, you can do it with any ball you want to get any color you want (even black from the 8B).