If tomato sauces are turning your plastic containers red, try this simple method of removing tomato stains.
When I store tomato-based sauces in plastic refrigerator dishes, or microwave such foods as chili and spaghetti sauce in plastic bowls, I usually end up with stains in the containers. I didn't want that, so I found a way of removing tomato stains: put a few tablespoons of lemon juice in each dish, fill it with water, and let it soak. In a short time, the stains are gone.
West Haven, Connecticut