Discovered red paint on the rear drums

So once I got through the scale, rust, and poorly sprayed black paint. I found red paint on my rear drums but didn't appear to cover the whole drum. It seemed to stop about where the fins start on the drum. I've heard that this means the car would have been equipped with optional wheels. Is this true? and would the front drums have been painted the same? The car is a '69 Roadrunner and I have no build sheet to confirm anything so it is all investigative work.

Thats kind of funny...I had rd drums on the rear of my gtx...I just figured that some bone head with bad taste got a hold of the car!!
Petty blue 67 gTx
49th helicopter transportation unit CA ANG 82 to 89

Lol. Yeah I've been looking around the internet trying to find some info and it looks like a while back moparmuscle did a restoration article and stated that the factory painted the rear drums if the car was optioned with magnum or ralleye wheels. Given that my car is a pretty standard 383 auto/column, am radio. It has some weird options...Light package, factory rubber mats,rocker mouldings, and now optional wheels. It makes me wonder why the person that bought my car off the show room didn't just go ahead and get an 8 track, tach, or clock for that matter.

Yes, the drums were painted at the factory on the outward facing surface if the car was factory equipped with the five spoke road wheels.