To draw on macarons, you can use an edible marker to make designs on macarons.
Edible markers come in various colors, not just black.
Black is the most versatile color, that can be used on any bright colored macarons.
You need to be quite gentle when drawing on macarons, because you do not want to pierce the shell.
You can make characters with your macarons first, and then add the details by drawing with your edible marker after.
You’ll want to make the shells, fill the macarons, and then draw on the macaron shells. Usually you would only want to draw on one side of the macaron. Have the drawn side up when displaying for your guests.