For all help and discussion relating to visual effects in programs that are not already covered in an existing forum, such as Blender, Particle Illusion, etc., along with discussion about effects theories and techniques.
I have the plugin, and after messing around with Gradient Map for a bit, I achieved a very similar effect. You just use Gradient Map in Vegas. The pictures below have the 3 Duochrome settings that were shown in the preview you gave (Acid Trip, Negative, and Fire Glow)? If you zoom in you should be able to see the settings within Gradient Map for each. Hope I understood what you were asking : )