Smart Color automobile Mercedes-Benz Nappa shell gray Leather repair leather dye for leather and artificial leather. 30ml leather dye 30ml leather sealant 1 sponges 2 Disposable glove With the SMART COLOR leather dye the color of the original leather is restored. Leather Color Apply the leather color evenly to the affected areas using a sponge or paint gun. The product is water-based. The leather dye has approval for surface-dyed car leather, furniture leather and aircraft leather.