Maybe, and I'll try that. Or maybe I'll just replace the UIColor in my model with a SwiftUI Color.

Here is a far simplfied version of the problem though without a viewModel. Any idea how to get it to work?:

import SwiftUI

struct ZColorPicker: View {

    @State private var bgColor = Color.systemTeal

    @State private var uiColor: UIColor = UIColor.systemOrange

    var body: some View {
        VStack {
            Circle()
                .frame(width: radius, height: radius)
                .foregroundColor(Color(bgColor.uiColor()))

             ColorPicker("", selection: Color($uiColor))
                .padding(.trailing, 30)
            Spacer()
        }
        .padding(.top)
    }
    let radius: CGFloat = 80

}

This one is telling me to file a bug report :D

Failed to produce diagnostic for expression; please file a bug report