Click with the mouse and drag it to draw. To not draw, just don't press on the mouse. Click the colour buttons to change the colour of your line. Click clear to clear what you have drawn. Click the rubber to rub marks out. Use the left and right arrow keys to change the size of the line you want to draw. Use the up and down arrow keys to change colouring pages.
I thank Yellow Dolphin for this project because now this is one of the most complicated project I have ever shared (except for my diggerball one).