Torque box (hog trough) color

[64studeavanti]

I have just finished cleaning the hog troughs on R4551. After removing  a bit of undercoating and surface rust, they look like new. I did break off one of the body mount bolts and one of the seat belt nuts came loose. Both have been repaired.  FWIW, this car spent most of its life in Los Angeles before coming to FL, according to the past registration receipts in the glove box.  

In any case,  they appear to have been painted black from the factory. The only other color on them is some over spray from the body (turquoise). 

While I  not a big fan, I am considering POR 15. Since I cleaned them up with a wire brush on a drill, I am sure I did not remove all the rust.

Any recommendations as to color? POR 15?

The Authenticity Manual does not address hog trough color. 

[silverstude]

Outside paint is a plus, but if you're going the POR15 route, consider opening up the door sills with a hole saw  every foot or so and do the inside of the troughs too.  That would be much more beneficial to the longevity.