Black lint on your photographs usually occurs in the camera during exposure. The lint on the film during exposure, casts a shadow on the film, creating a clear image of the lint on the finished negative. When printed, the lint appears dark or black on the finished print. If you are experiencing problems with dark colored lint, remove the film from your camera and carefully clean inside the film area.
Light colored scratches on your prints can often be eliminated during printing, by using scratch covering products available commercially. Sometimes they disappear completely, and other times they cover only partially. Colored or dark scratches are not nearly as easy to deal with. They are blackish or colored because they are scratched into or completely through the dye layers of the negative. They cannot be hidden by scratch covering products. Digital imaging processes and artists can almost always remove these types of scratches, but be prepared to pay for their time.