Darren, rugs are meant to go on hard floors, not on carpet.
I believe that originally they were put down on dirt floors.
Now they go on tiles as well as timber and other hard flooring.
To prevent that from happening again is easy.
When I'm asked how to stop the cat or dog peeing on the carpet, I tell them to keep the animal out of any carpeted rooms.
Same with the rug, to prevent the same from happening, don't put it on the carpet.
Plastic under the rug could sweat, producing moisture which may form mould (mold for the Yanks ;-) ), then you will have a health issue as well.
It may also cause either or both, the carpet or rug to rot.
Waiting several days/weeks before placing the rug on the carpet?
Refer to line six.
If anyone wants to put a rug onto carpet, they do so at their own risk.
Some others here may have a better suggestion for you.
Apologies to Dave, I never read that post of yours before,
& yes, it does sound like what he has described, being the pink tinge and all.
Wish we could see pics of all these different problems so we may better relate to the problem.
