Marshall BKA Brandess Kalt-Aetna Marshall spot-all retouching color - natural black 15mlMarshall Selenium Brown is a retouching dye for photos on RC and FB paper Marshall retouching dye is the result of years of research by American company BKA (Brandness Kalt Aetna). The Spot all Kit is designed especially for retouching, coloring and correcting B&W positives and negatives. The colors are completely absorbed by the emulsion and are rapid drying. They can be used on almost all types of film and photo paper, whether it is matte or glossy.