DeColourant and DeColourant Plus

http://www.dharmatrading.com/html/eng/10073753-AA.shtml

Use deColourant to remove the color from dyed natural fabrics, such as cotton, rayon, or linen. deColourant also works on many papers. It will remove the dyed color and leave the natural undyed color of the item, depending, of course, on what the item is dyed with originally.

deColourant Plus acts the same way as deColourant, but in one step it removes the color (like deColourant) and adds a new color to replace the removed color. Basically, deColourant Plus is deColourant creme with pigments already added. In a single pass, deColourant Plus both removes the dyed color from natural fibers and replaces that color with the deColourant Plus pigment

You can get it from dharmatrading.com