New Post: Composite ImageMagick equivalent in Magick.NET

I downloaded last release and I tried to make it work for two days but no success :(
Maybe I am missing something but I don't know how to compose 3 images using Magick.NET.
Starting with Trax63 code :

           var args = "100,0";
           MagickImage ret = img.Copy();

            MagickImage filter1 = img.Copy();

            filter1.Colorize(color, new Percentage(100));

            MagickImage filter2 = img.Copy();

            filter2.ColorSpace = ColorSpace.GRAY;
            filter2.Negate();

What should I write to get the final result? I tried many combination but it did not work, If I just write only what you give me :

img.Composite(filter2, Gravity.Center, CompositeOperator.Blend, args);

I guess I'm missing something...but cannot figure it out.