The base color will affect the color coat itself. Anything Mirra chrome related will need a smooth gloss black base. That base is as important as the overcoat with Mirra chrome. I've had to do silicone break away mirrors this way. Get the silicone tinted as black as possible then dust it with Mirra chrome. You will not be able to handle it however so it's use is limited.
Prior to that I had used clear silicone with a mirrored mylar backing then buffed the surface of the clear silicone with a fine mesh aluminum powder. It was a good enough reflection to pass on camera. But not a mirror reflection.
Mirra chrome and other air brush applied chromed paints are all pretty much the same thing. And expensive. Just Google Mirra chrome. See if you can find anything off that research that works with silicone.