Ok, here we go!
The US nuke boats have a demarcation line at the main axis (along the length) of the ship. As delivered, they were black from the waterline up, and hull red from the waterline down. They didn't stay that way. Below the main axis line is hull red for everything older than Seawolf. From the waterline down to the main axis is hull red with 1 coat of black over it. It almost looks purple! From the waterline up is black. The main axis line also splits the upper and lower surfaces of the stern planes, red under, red/black on top.
Why does this keep coming up? There have been discussions on this before.
There are some pictures of my Trepang out there wearing the proper war paint. I don't have any here at home, but can retrieve them and send next Monday. There is one pic of her submerged at Johnston, RI on my members page. There may be others amongst the 'Regatta pics. She carries the hull number 674 on the sail.
"If you ignore the problem long enough, it will go away. Even flooding stops eventually!"