Hold the space bar to draw. To not draw, just don't hold the space bar down. Click the color buttons to change the color. Click clear to clear what you have drawn. Use the left and right arrow keys to change the width. Use the up and down arrow keys to change the shade of the color.
Credits to @Yellow_Dolphin for the original please follow, i have no followers at this time, i want t start making friends on scratch, so drop a comment