I had to replace the rear bumper on our vehicle after it was damaged in a parking lot. Since I wasn't going to get any $ out of the person, I sourced a CAPA certified bumper. The colour of the bumper is close to stock, but it is lighter than the adjacent trim found along the body sides. It is noticeable to me and I'd like to darken the grey of the replacement bumper. The bumpers on my model are not colour matched to the body. Is there a way to darken plastic, without painting it? It's not an armor-all situation, I need to darken the bumper, using dye or something similar.