Screenshots on iPhone and iPad get darker than the original image.
When taking a screenshot on iPhone or iPad the colors shift to be slightly darker. It appears that this started since IOS and iPadOs 18. Some colors seem to be affected more than others (I find that they tend to be pastels). Some colors don't seem to be affected but, it's still a major issue, especially for people that do anything with photos (which is basically everyone).
(The first photo is the original. Each subsequent photo is a screenshot of the previous one. If for some reason these get posted out of order, the order of the screenshot is from lighter to darker. Here you can see the color shift):
iPhone 16 Pro Max, iOS 18