Tomato sauce will stain but odors should wash away. There shouldn’t be much fat in tomato sauce.

How about just plain tomatoes that have been pureed?

Same thing, less concentrated, less stain.

It is the acid in the tomatoes that will discolor the plastic. Basically it is burning itself into the plastic.

What kind of plastic? Not Formica, not plastic bags, not plastic forks, not plastic wrap; I’m confused.

Basically tupperware.

Tomatoes of almost any kind do stain tupperware particularly if you microwave them in it.