I'm going to ask my dad if he had repainted that grill, I doubt he did though. It's tough to see in the pictures bc the car is dusty and inside, but I'll come back later on and make a diagram deal to help you out more.
The paint is not like the rear panel at all, very little texture at all is felt and I would guess thats just bc its a plastic painted piece. Most of it is dark gray and some is a lighter silver. The bars in back are black, but you can see in one picture how the silver/gray has gone up 1/4 of the way on the bar.(last picture)
Basically you would paint from the front the silverish color on the parts that come to a point (very front of the fins). Then I would spray the rest from the back. Not going to be easy, but good luck. But like I said I'll come back tonight with the answer to if my dad had painted these and add some arrows to show the color differences.