CG Bob
18' 6" draft mark (waterline); the upper edge is at 22'.
Excellent research there.
To OP: Note that the strip is not a consistent 18" wide. It runs from the waterline elevations of 18.5' to 22' where the hull slopes or curves between those two elevations, the strip can be significantly wider that 18"
This is why many "how-to" recommend having the hull be level to her water line over some flat surface like a table or bench. You then set a pencil or scribe at the bottom extent and draw that line right around the hull, and repeat for the upper extent.
This gets finicky, as six inches--the height of USN draft marks is 0.017" at 1/350 scale (0.435mm) which is not that much more than 1/64 inch.
OP may have noticed, too, that USN ships use Deck Gray for their horizontal surfaces. What model color best replicates that stirs debate. A person can advocate for colors as diverse as Dark Gull Gray or Gunship Gray (most "Panzer Grays" scan a touch too blue).
In addition, USN uses a special coating on flight decks. One of the best descriptions of the color is "asphalt"--so any hue from near black to very dark gray with brown tones (but it should be noticebly darker than the Deck Gray.
As TankerBuilder points out, when new the paint is often a starker color than after 3-4 weeks' sun exposure. To further confuse things, a Burke will have 40-60 personnel onboard whose only job is to maintain topside paint, so there will be areas of fresher paint over older, which, until the next Yard period, gives a patchwork sort of appearance that's very hard to model at small scale.
Many of the Burkes will seem to have a darker hull than topsides in some photos and the reverse in others, so a person wants to use several refernce photos in selecting a color before going to specific ship photos to look for any unique applications of those colors.