Eu sou novo no trabalho com Bitmap e usando 16 bits por pixelFormat16bppRgb555;

Quero extrair valores RGB de dados de bitmap. Aqui está o meu código

static void Main(string[] args)
    {

        BitmapRGBValues();
        Console.ReadKey();
    }


 static unsafe void BitmapRGBValues()
    {

        Bitmap cur = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format16bppRgb555);
        //Capture Screen
        var screenBounds = Screen.PrimaryScreen.Bounds;
        using (var gfxScreenshot = Graphics.FromImage(cur))
        {
            gfxScreenshot.CopyFromScreen(screenBounds.X, screenBounds.Y, 0, 0, screenBounds.Size, CopyPixelOperation.SourceCopy);
        }

        var curBitmapData = cur.LockBits(new Rectangle(0, 0, cur.Width, cur.Height),
                                 ImageLockMode.ReadWrite, PixelFormat.Format16bppRgb555);


        try
        {
            byte* scan0 = (byte*)curBitmapData.Scan0.ToPointer();

            for (int y = 0; y < cur.Height; ++y)
            {
                ulong* curRow = (ulong*)(scan0 + curBitmapData.Stride * y);

                for (int x = 0; x < curBitmapData.Stride / 8; ++x)
                {

                    ulong pixel = curRow[x];

                    //How to get RGB Values  from pixel;







                }

            }


        }
        catch
        {

        }
        finally
        {
            cur.UnlockBits(curBitmapData);

        }


    }