If you are using SwiftUI to build your apps, there is a fairly basic but very useful Accessibility Inspector built right there in the Inspectors Panel, on the right side of Xcode.
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As with UIKit, in SwiftUI you can also add/remove a11y traits. But because of its declarative nature, you'll have to approach it in a slightly different way. A little nuance, but something that made me scratch my UIKit head when learning SwitUI.
iOS and Xcode provide a wide variety of tools and options to deal with color contrast ratios. From system colors, that automatically support Increase Contrast, to high contrast color and asset variants, and even a built-in contrast calculator.
The Accessibility Inspector can be used with your device. It is actually quite interesting to check what other apps (or iOS) configure, for some of the basic accessibility attributes (label, value, traits, hint...), in their UI components.
