I would think another washing and it would come out. My neighbor uses the blue and white but one thing she told me she does before washing is she takes a very soft make up brush that has never been used for makeup and brushes all over it. She says it loosens the chalk. Then she uses the attachment on her vacuum and gets as much as she can. She doesn't hold it right up against the fabric but it helps to lift the chalk. Works for her and she only washes it once.