I don't think black works for the upper colour, it needs to be a very dark grey colour. Revell Anthracite is a good 'off black' colour. This can be weathered with slightly lighter colours for vertical streaking. Plus a hard black can be used for random panels, which will then stand out.
I think the Los Angeles class has a red lower hull, below the mid point of the hull. Dry dock photos, from memory, often show a washed out salmon pink sort of colour, indicating extreme wear and tear. So my thoughts would be anything from a flat primer red brown to a very washed out red/pink sort of colour..How is that for vague??