If George doesn't know something better, I have used Resolve tough stain carpet cleaner and gotten out old stains without taking color out of any fabric SO FAR. Perhaps you could use a soft tooth brush to rub it in? It might take more than a couple of applications. But I have even gotten an old glue footprint out of carpet without any damage to the color of the carpet. Also ground in chewing gum. Even blood. I have used it on stains on clothing too. So far so good, but only used when nothing else seemed to work.