Turmeric stains fade in the sun. Tomato stains are a tougher fight.

Turmeric stains respond to sunlight, and tomato stains need an oil-based cleaner.

For turmeric, the old trick actually works. Wash the container with soap, leave it slightly wet, and put it in direct sunlight for a few hours. The UV rays break down the curcumin molecule, and the yellow basically disappears. Even a cloudy day can help, but bright sun is fastest.

Tomato is different. The red-orange comes from carotenoids, which are oil-soluble. So dry scrubbing won’t cut it. Rub a little cooking oil or oil-based cleanser over the stain, let it sit a few minutes, then wash with dish soap. A paste of baking soda and a splash of dish soap works well too as a mild abrasive.

But here’s the honest part: if the stain has been in there for a while, it’s probably soaked into the plastic itself. Scratched-up or cheap plastic holds onto these pigments permanently. At that point, you’re not really cleaning — you’re peeling off a layer of the container. That’s when you recycle it and get a glass or stainless steel container for your curry.

Sometimes the stain is the price of a convenient lunch.