SwiftUI | ライトモード/ダークモードに応じて変化する色の設定方法

Rectangle().foregroundColor(.primary)
Rectangle().foregroundColor(.secondary)
Rectangle().foregroundColor(.accentColor)
Rectangle().foregroundColor(Color(UIColor.systemRed))
Rectangle().foregroundColor(Color(UIColor.systemGreen))
Rectangle().foregroundColor(Color(UIColor.systemBlue))
Rectangle().foregroundColor(Color(UIColor.systemCyan))
Rectangle().foregroundColor(Color(UIColor.systemMint))
Rectangle().foregroundColor(Color(UIColor.systemPink))
Rectangle().foregroundColor(Color(UIColor.systemTeal))
Rectangle().foregroundColor(Color(UIColor.systemBrown))
Rectangle().foregroundColor(Color(UIColor.systemIndigo))
Rectangle().foregroundColor(Color(UIColor.systemOrange))
Rectangle().foregroundColor(Color(UIColor.systemPurple))
Rectangle().foregroundColor(Color(UIColor.systemYellow))
Rectangle().foregroundColor(Color(UIColor.systemGray))
Rectangle().foregroundColor(Color(UIColor.systemGray2))
Rectangle().foregroundColor(Color(UIColor.systemGray3))
Rectangle().foregroundColor(Color(UIColor.systemGray4))
Rectangle().foregroundColor(Color(UIColor.systemGray5))
Rectangle().foregroundColor(Color(UIColor.systemGray6))
Rectangle().foregroundColor(Color(UIColor.systemFill))
Rectangle().foregroundColor(Color(UIColor.secondarySystemFill))
Rectangle().foregroundColor(Color(UIColor.tertiarySystemFill))
Rectangle().foregroundColor(Color(UIColor.quaternarySystemFill))
Rectangle().foregroundColor(Color(UIColor.systemBackground))
Rectangle().foregroundColor(Color(UIColor.secondarySystemBackground))
Rectangle().foregroundColor(Color(UIColor.tertiarySystemBackground))
Rectangle().foregroundColor(Color(UIColor.systemGroupedBackground))
Rectangle().foregroundColor(Color(UIColor.secondarySystemGroupedBackground))
Rectangle().foregroundColor(Color(UIColor.tertiarySystemGroupedBackground))

import SwiftUI

struct ContentView: View {
    var body: some View {
        ScrollView {
            VStack {
                cell(text: "primary", color: .primary)
                cell(text: "secondary", color: .secondary)
                cell(text: "accentColor", color: .accentColor)
            }
            VStack {
                cell(text: "systemRed", color: Color(UIColor.systemRed))
                cell(text: "systemGreen", color: Color(UIColor.systemGreen))
                cell(text: "systemBlue", color: Color(UIColor.systemBlue))
            }
            VStack {
                cell(text: "systemCyan", color: Color(UIColor.systemCyan))
                cell(text: "systemMint", color: Color(UIColor.systemMint))
                cell(text: "systemPink", color: Color(UIColor.systemPink))
                cell(text: "systemTeal", color: Color(UIColor.systemTeal))
                cell(text: "systemBrown", color: Color(UIColor.systemBrown))
                cell(text: "systemIndigo", color: Color(UIColor.systemIndigo))
                cell(text: "systemOrange", color: Color(UIColor.systemOrange))
                cell(text: "systemPurple", color: Color(UIColor.systemPurple))
                cell(text: "systemYellow", color: Color(UIColor.systemYellow))
            }
            VStack {
                cell(text: "systemGray", color: Color(UIColor.systemGray))
                cell(text: "systemGray2", color: Color(UIColor.systemGray2))
                cell(text: "systemGray3", color: Color(UIColor.systemGray3))
                cell(text: "systemGray4", color: Color(UIColor.systemGray4))
                cell(text: "systemGray5", color: Color(UIColor.systemGray5))
                cell(text: "systemGray6", color: Color(UIColor.systemGray6))
            }
            VStack {
                cell(text: "systemFill", color: Color(UIColor.systemFill))
                cell(text: "secondarySystemFill", color: Color(UIColor.secondarySystemFill))
                cell(text: "tertiarySystemFill", color: Color(UIColor.tertiarySystemFill))
                cell(text: "quaternarySystemFill", color: Color(UIColor.quaternarySystemFill))
            }
            VStack {
                cell(text: "systemBackground", color: Color(UIColor.systemBackground))
                cell(text: "secondarySystemBackground", color: Color(UIColor.secondarySystemBackground))
                cell(text: "tertiarySystemBackground", color: Color(UIColor.tertiarySystemBackground))
            }
            VStack {
                cell(text: "systemGroupedBackground", color: Color(UIColor.systemGroupedBackground))
                cell(text: "secondarySystemGroupedBackground", color: Color(UIColor.secondarySystemGroupedBackground))
                cell(text: "tertiarySystemGroupedBackground", color: Color(UIColor.tertiarySystemGroupedBackground))
            }
        }
    }
    
    func cell(text: String, color: Color) -> some View {
        return VStack {
            HStack {
                Text(text)
                    .frame(width:200, height: 35)
                Rectangle()
                    .foregroundColor(color)
                    .frame(width: 150, height: 35)
            }
        }
    }
}