I sprayed white paint first over the black, then I mixed in some yellow, then orange, and finally I darkened it to red. This way the red didn't turn pink on me.
Here are the results . . .
I know I messed up in a couple of places with diamonds that don't connect, but hopefully this is where some well-placed rust spots might come in handy!!!
I might also come back in and dot some gold where all the diamond tips touch . . .