How can I see it as a non-black material ? Nir
I don't understand, can you show a picture for an example? in this one, it's a boolean difference between to spheres. The one that has the cut removed is red, obviously, but the one doing the cutting is blue. The black in this is just a shadow. Always, the material on the object doing the cutting will be the material that you see along the cut contour. To make the boolean object all the same material, apply the same material to all objects involved. Unless you're having a display problem or something else, which I can't tell by your description.
