system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: Why is tomato-sauce so good at coloring plastic red in your dishwasher, unlike raspberries or strawberries for example?

We like tomato sauce, but one must be careful with what to put into the dishwasher, to not have plastic bowls, storage boxes or other things dyed red...Why is tomato sauce this potent in coloring plastic. It's like it's in the fabric of the plastic itself after it comes out of the dishwasher...why not the same effect with strawberries or raspberries? And is there a way to prevent this?

Edit: Wow, this got some momentum...I see a lot of people like tomato sauces. Thanks for the awards as well!
gpt
The colour in tomatoes that makes them red, and it is very concentrated in tomato sauce, is lycopene. 

Lycopene loves plastic, it sticks to it and doesn’t want to let go. Similar to the yellow pigment in Tumeric (that spice in curry that turns everything a funny yellow colour). When a pigment sticks to a surface that well, it’s essentially dyed that colour. Because the pigment has bonded with the surface. You can’t just “wash it off”. 

That red molecule isn’t in raspberries or strawberries. It’s different pigments that cause that and it’s not as adherent (sticky) to plastics. 

 Prevention - most simply, use glass or ceramics instead of plastic. It’s better anyway, will go in the oven, will go in the microwave, easy to clean, no roughness on the surface that germs can get stuck in, don’t get scratched by knives, generally amazing stuff. 

If you absolutely cannot live without plastic in your kitchen, you can try putting a thin layer of oil on the plastic, to keep the pigment from contacting the container. 

You can try to do some research on the molecule lycopene, and work out if there is an easy way to get it to release the plastic. See if washing it in vinegar gets it to let go, or whatever.