Actually, On darker fabric I have always used the Clover WHITE chalk wheel liner. They have remade this product so I haven't tried this version.
http://www.joann.com/clover-pen-styl...+chalk&start=1
DO NOT EVER use the blue or yellow without first doing a color check to make sure the product is removable. I have never had a problem with the white, it wipes off easily. I used this on all my quilts that won me ribbons including my avatar.