I am not sure if Magick.NET will be the right tool for you if you need a "100% true way". Look at this part from the documentation (http://www.imagemagick.org/script/color-management.php):
ImageMagick supports color profiles, however, for images without a profile or a declaration of colorspace, ImageMagick assumes non-linear sRGB.image.GetAttribute("icc:model") looks at the color profile and returns the name from an embedded profile if it exists.