69 F Body Rear Axle Color *Latest Consensus*

[RamAirBirds]

What i the latest/final consensus on the finish for the rear axle on the Camaro/Firebird.
When I look in the "Legends Judging Manual" it does not really state anything other than Black Backing Plates but the axles they show in the photos appear to be all Black.
To this point I had always painted the axle Tubes Natural Steel and the Center Section in Cast Iron Color. Also i have seen some people spray the back of the assembly with a light coverage of black like it was over sprayed while in the car during bottom finish. What is the latest and greatest method out there.
Can somebody please shed some light on this?
Specifically ready to paint a couple 69 RA Firebird Axles, a 69 Camaro 12 Bolt and a 68 RA GTO Axle.
Any help and thoughts/discussion is appreciated. Need to hear from the experts out there. Thanks in advance. If this has been covered if you could point me to the proper thread would also be helpful.
RA