Can you wash off fabric marker?
Fabric markers contain permanent color that is designed to not wash out of clothing or fade over time. To remove fabric marker, apply hydrogen peroxide or your preferred stain remover to the area while the ink is still wet. After the ink has dried, the color will be permanent on the fabric. Rub the hydrogen peroxide into the fabric to loosen the pigment and pat dry. Repeat as needed to remove the ink and wash fabric. This will remove most of the color from the fabric.