After a month of extremely hard work my sister and I finally finished roofing my mothers house. We are both college students and decided to spend the summer building her a new roof to help avoid the huge costs of hiring a contractor. I can honestly say we did quality work. The new sheeting was awful to put on but we figured it out. The shingles square up at the eaves and ridge. The flashing looks good. Overall the new roof looks great except for one thing. The shingles are already turning brown!!! We bought Sentinel 25 year silver tinting(basically white) shingles from Home Depot. We purchased all our materials from Home Depot. After just one month the shingles already look old. It appears that the adhesive tar material that holds down each shingle is starting to get sucked up into the shingles and and discolor them. Is there anything we can do at all? Its heartbreaking to put so much effort into something only to have it look bad. We used 7/16 OSB sheeting spaced properly and 15 weight felt over the entire roof so I don't think the heat from the attic would be killing the shingles already. Is this a manufacter's defect? Any help would be greatly appreciated.

the roof is old and moldy. My bro-in-law thinks he can just put a metal roof over the old comp roof. I think it should be ripped off and the metal roof should go on new plywood. he thinks the old roof would be a good insulator. I think the old roof will cause the rafters to rot, and the new roof to be rippled and wavy.. Anyone have any clue as to who is right?? And what is the normal thing to do??