Off-topic, but I'm facing an issue with sharing UserDefaults data between iOS and watchOS (including the complication). You cannot use shared UserDefaults cross-device, it only works cross-extension on the same device, e.g. for sharing data between main app and Widgets extension. To share data between iPhone and Watch you must use WatchConnectivity. Check out my WKComplications example on GitHub for working example.

You should use the new modifier introduced in iOS 18: .widgetAccentedRenderingMode(.fullColor). It allows to override view rendering mode.