I had the same problem on the backside of a belt. Front side was dyed with Fiebings Dark Chocolate Pro Dye. The flesh side needed to be smooth and dark color. I used black Tokonole to get both. Glassed the Tokonole and got smooth and dark color. Looks great. Then I water tested with a damp paper towel and the black Tokonole transferred from the back side to the towel. I applied 2 light coats of Mop & Glo and there are no more color transfer issues. The edges had been burnished before doing the back side and the gloss dulled down from Mop & Glo. A light burnish with canvas on the edges restored the high gloss.
