I have black leather seats in my 77. They are in nice shape but they are worn some, no tears but they are faded to a grey color, black mostly but grey where some grain is. I would like them to be solid dark black. I can put on some leather dye but I am worried about the dye transferring to clothes. Is there a good way to do this? Solid seat covers, don't need to be replaced but would be nice to see them dark black again!!