I have not enougth know how in Visionaire. 
But because I want to use the same effect later I search for a solutuion
I have not found to set the rendering methode for objects and sprites. 
Helpfull will be multiplication, or add.
I found a hint in a 2 years old forum post. 
You can do with partice. But dont write how. 
Partikel have a rendermode: add
http://wiki.visionaire2d.net/index.php?title=Particle_RenderingMaybe make a emitter with no speed, very long lifetime and move it around by lua-script?
Rendermode for object or sprite will be nice 
