I have a house that is approximately 25 years old with the origonal vinyl siding. (white in color) It shows some chalking, but not too bad. In some areas, shadows have developed as if dust has impregnated itself into the vinyl. It is not mold. I have tried cleaning with TSP, bleach, and a combination of TSP and bleach. The "shadowing" remains. Can I paint the siding with any long - term success? Thanks in advance, Dodgeman