I used a mechanical lead pencil to mark a light pink and cream colored quilt for my grand-daughter. After washing in the machine with Oxyclean none of the marks came out. I ended up putting it in the kitchen sink and scrubbing the marks out with an old tooth brush. Not that I am recommending this method, although it did work, just commiserating with you. I don't think all is lost for your quilt though. Good luck.