Click on a marker on the left side to choose a color.
Place your cursor where you want to color, then move it around to color.
To change colors, choose a different marker.
To change the width of the marker, choose a different “Marker Size” on the right side.
To erase, click on the eraser on the right side, then move your cursor over the color you want to erase. To begin coloring again, click on the marker on the right side, then choose a marker color on the left side.