Platforms Impacted

• iOS
• visionOS
• macOS

Description of changes

The APIs for creating a UIColor from SwiftUI Color don't work properly on iOS 17 when the Color is dynamic. This works fine on iOS 18, but results in dark mode issues on iOS 17.

Solution: reverting back to an older implementation of UIColor creation, with a few extra public markers to make it work in the new Fluent infrastructure.

Verification

(how the change was tested, including both manual and automated tests)

Visual Verification

Before	After

Pull request checklist

This PR has considered:

• Light and Dark appearances
• iOS supported versions (all major versions greater than or equal current target deployment version)
• VoiceOver and Keyboard Accessibility
• Internationalization and Right to Left layouts
• Different resolutions (1x, 2x, 3x)
• Size classes and window sizes (iPhone vs iPad, notched devices, multitasking, different window sizes, etc)
• iPad Pointer interaction
• SwiftUI consumption (validation or new demo scenarios needed)
• Objective-C exposure (provide it only if needed)

Microsoft Reviewers: Open in CodeFlow