Am very famliar with that color. I dont know if they offer such things in the OMNI line like they do with the regular PPG stuff, but adding hardner to the basecoat will help control the metallics.
Dont add hardner to whole batch just add it to what you mix up to spray.
Another thing you can get is clear basecoat, the DBC part number is DBC500, once again I dont remember if its offered in the OMNI line.
You spray your basecoat getting coverage first. Then on the last coat or two I mixed in that DBC500 at a 50% ratio. What that does is kinda thin it down but not really, helps control the metallics.
But those two things are NOT cure all's if you have poor gun setup and spray technique. Those are biggest effects on metallic control.
Also the proper reducer plays a HUGE factor in metallic layout. Make sure you have the right reducer for the temps.
Make sure your gun is setup right and pratice getting 50% overlap, you can use straight lacquer thinner for this. Spray on some cardboard and watch your spray pattern and overlap.
IMO, dusting a color should be a last resort, not a cover for poor setup and technique. Eventho dusting on some colors is 100% needed its not the cure all.
Brian's got a good write up on "dusting" color...Eric