I usually pack leftovers for lunch. We have lots of plastic containers, but they are always getting stained. To help prevent these stains you can try a couple of things. Cooling the container and lid in cold water for a few minutes before filling works pretty good. It is also helpful if the food has cooled and you don't reheat the food in the container. If you have to reheat the food in the container try coating the inside with olive oil. Just put a little on a paper towel and spread it around before filling. There are several new products on the market that are not supposed to stain, but they are much more expensive than the disposable variety.
