Changing the color of the title bar in WinForm

I created a C# class using @Jonas Kohls answer from here

The class works like a charm and makes it easy to work with multiple forms just call DarkTitleBarClass.UseImmersiveDarkMode(Handle, true); in your load method.

I used this when upgrading some old WinForms apps so its WinForm friendly but only tested on win 8,10 and 11

Example image below Winforms .NetCore 6.0

using System.Runtime.InteropServices;

namespace Myapp.Classes
{
internal class DarkTitleBarClass
{
    [DllImport("dwmapi.dll")]
    private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, 
    ref int attrValue, int attrSize);

    private const int DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1 = 19;
    private const int DWMWA_USE_IMMERSIVE_DARK_MODE = 20;

    internal static bool UseImmersiveDarkMode(IntPtr handle, bool enabled)
    {
        if (IsWindows10OrGreater(17763))
        {
            var attribute = DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1;
            if (IsWindows10OrGreater(18985))
            {
                attribute = DWMWA_USE_IMMERSIVE_DARK_MODE;
            }

            int useImmersiveDarkMode = enabled ? 1 : 0;
            return DwmSetWindowAttribute(handle, attribute, ref useImmersiveDarkMode, sizeof(int)) == 0;
        }

        return false;
    }

    private static bool IsWindows10OrGreater(int build = -1)
    {
        return Environment.OSVersion.Version.Major >= 10 && Environment.OSVersion.Version.Build >= build;
    }
  }
}

[EDIT] Don't forget to add a app.manifest and uncomment the appropriate supported OS.

If you want to have a title bar different from others, consider getting a Community license for this

I tried once and it worked. I just had to install it and change Form to SfForm

This is the using statement

using Syncfusion.WinForms.Controls;

The references for WinForms are Syncfusion.Core.WinForms and Syncfusion.Shared.Base