Change Theme color (Dark/Light mode) FAST!

Program.cs

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;

class Program
{
    [DllImport("user32.dll", SetLastError = true)]
    static extern bool SendNotifyMessage(IntPtr hWnd, uint Msg, UIntPtr wParam, string lParam);

    static void Main(string[] args)
    {
        int LightTheme = 0;

        if (args.Length > 0)
        {
            if (int.TryParse(args[0], out var val))
            {
                if (val > 1)
                    LightTheme = 1;
                else if (val < 0)
                    LightTheme = 0;
                else
                    LightTheme = val;
            }
        }

        RegistryKey k = RegistryKey.OpenBaseKey(RegistryHive.CurrentUser, RegistryView.Default);
        var wr = k.OpenSubKey(@"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize", true);

        wr.SetValue("AppsUseLightTheme", LightTheme, RegistryValueKind.DWord);
        wr.SetValue("SystemUsesLightTheme", LightTheme, RegistryValueKind.DWord);
        SendNotifyMessage((IntPtr)0xffff /* Broadcast */, 0x031A, (UIntPtr)0, ""); //WM_THEMECHANGED
    }
}