The USN anti fouling usually starts off red/brown, the color of red lead paint. Some photos show it fairly bright red and glossy, but that's usually due to lighting and processing. There are other colors of anti fouling, blue, green, black, but unless the ship was in a private yard that couldn't get the red stuff, then it would be red/brown. Now there is a bright blue coating being used.
The reason you are seeing blue grey is that the red/brown fades and wears off and gets dirty, so you see all sorts of colors when it comes out of water for cleaning and reprinting. Blue, grey, green, black, white staining.
Tamiya paint is fine, they have a red brown that is close. You can add more red if you think it needs it.
The boot top is black and the rest of the ship is haze grey, but you probably won't find an exact match for that one.
I starting to get into model building again and haven't done it since I was in my 20's (I'm 47 now). I purchased a 1/350 resin destroyer (U.S.S. Johnston DD-821) that is the same class and refit as the ship my father was on in the late 60's-early 70's (U.S.S.Bordelon DD-881). I want to try to get the color scheme as close as possible to when he was deployed and was asking for some assistance. Based on photos I've been searching, the anti fouling appears to be black or extremely dark blue-gray? Could anyone provide some assistance and maybe color codes? I'm using Tamiya Acrylics but am open for other paints if they are better suited. Thank you for any assistance and advice!