I boiled sliced yellow squash with ravioli, and it turned bluish-green -- why?
Boiled cheese ravioli for 10 minutes. Added sliced yellow squash for the last 3 minutes. Nothing else in the pot but boiling water, not even salt. It looked fine cooking but after I drained everything in the colander, the squash rind stayed yellow but the flesh turned bluish-green on most pieces. Not all pieces though. It tastes the same as usual. 
The color is freaky. Why did this happen?
Best Answer
Probably the same reason why garlic turns blue sometimes when you cook it. http://www.foodsafetysite.com/consumers/faq/?m_knowledgebase_article=14
its a reaction with sulfur + copper which can naturally occur in foods.
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Why did my yellow squash turn green?
Yellow Mosaic Disease The disease known as either yellow mosaic or squash mosaic virus turn yellow squash green, or appears as yellow and green mottling over the fruit, reveals the University of California Integrated Pest Management Program.Why is the inside of my spaghetti squash green?
The fact is that the answer depends on spaghetti squash ripeness, or how mature the squash is. If the squash is green and soft, it is more likely to rot than ripen off the vine. If, however, there are hints of yellow and the squash appears to be full sized and sounds solid when thumped, I would go ahead and try it.What does spoiled yellow squash look like?
Yellow squash is bad if the skin is mushy or spongy, and the skin should have a lustrous sheen and be worm-free. Squash with wrinkled or soft skin is likewise sour, and it should be mushy and rotten on the inside.Can you eat squash green?
Squash GreensThe leaves from squash and pumpkin plants are not only edible, but they are absolutely delicious and highly nutritious. In my opinion, onion and garlic are the key to scrumptious squash greens.Don't Hug me I'm Scared
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Answer 2
It's cucumber mosaic virus. It is still edible, just makes the food look less desirable and therefore not as marketable. Producers try to avoid/prevent it for that reason. But it is still fine and edible.
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