Edited Unassigned: Level-Colors command [1404]

I want to use the +level-colors (note the + sign) but it seems to be the -level-colors (note the - sign) method that is exposed in Magick.NET.

I want to color a transparent image like this example "convert cow.gif +level-colors red, cow_red.gif" on http://www.imagemagick.org/Usage/color_mods/#level-colors (also note that the second argument is empty)

Is this possible, or is the feature missing?