Sometimes we may fail to convey to the user of things changing on the screen in a perceivable way. Toasts and similar should be announced. We may want to make clear that some content on the screen changed. Or we might want to update on progress.
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Toggles or UISwitches are often found separated from the label that precedes (and describes) them; with an unclear label; missing a value, trait, or hint; or even not being actionable at all.
You should convey important information in multiple modes, not just color. If you are still required to do so, at the very least you should complement that info with other modes, like symbols, if the user requested differentiation without color.
Images can automatically scale for accessibility content size categories, by setting the adjustsImageSizeForAccessibilityContentSizeCategory property to true, for any UIImageView you'd like to get its size adjusted. https://developer.apple.com/documentation/uikit/uiaccessibilitycontentsizecategoryimageadjusting/adjustsimagesizeforaccessibilitycontentsizecategory
