【Swift】Color の RGB + Opacity の数値を求める 👉 https://android.benigumo.com/20240518/color-rgbo/

TestColorValues.swift

import SwiftUI

struct TestColorValues: View {
  var color: Color

  @Environment(\.self) private var environment

  private var resolved: Color.Resolved {
    color.resolve(in: environment)
  }

  var body: some View {
    VStack {
      Text("\(resolved)")
      Text(String(format: "R: %.3f", resolved.red))
      Text(String(format: "G: %.3f", resolved.green))
      Text(String(format: "B: %.3f", resolved.blue))
      Text(String(format: "O: %.3f", resolved.opacity))
    }
    .monospaced()
    .padding()
    .background(color)
  }
}

#Preview("TestColorValues") {
  VStack {
    TestColorValues(color: Color(.secondarySystemBackground))
      .environment(\.colorScheme, .light)
    TestColorValues(color: Color(.secondarySystemBackground))
      .environment(\.colorScheme, .dark)
  }
}