We've been through this before. I've seen salt corrode copper, and, yes, I've seen green pennies.
Some years back I did a small, not-very-systematic experiment (completely by accident). I had the grubby habit of eating lunch in my car at fast fooderies. I dopped a small handful of pennies in one of the coin holders. I accidentally spilled a little paper packet of salt into the cupholder as well. Then I set a large paper cup full of coke or something on top of the pennies. The pennies got wet from the dampness that wicked off the outside of the cup. I then forgot about them for a couple of weeks.
When I got around to taking the pennies out of the cupholder, the water was about 1/4" deep and the salt had completely dissoved. One penny was just a bit darker than when it was minted. One was dark-colored, with a verdigris green ring around it. (The green was partly made of a powder, which be brushed off. If you did brush it off, the copper underneath was greenish.) The third penny was pure black.
All sorts of things are scientifically wrong with this exercise in terms of providing evidence of what a ship's copper bottom would look like. The Constitution's bottom is green, and has been for a long time. (The red stripe along the waterline is the Navy's idea of making her look nice for visitors. Incidentally, am I the only one who cringes when that ship is referred to as "Connie"?) The Victory's bottom, as another contributer noted, has little copper left on it. (I've visited the ship twice, in 1978 and 1991. In all honesty, the complex framework of the drydock made it almost impossible to see anything below the waterline.)
There's an excellent chance that the metal on the Constitution is of a quite different chemical composition than what was on her in 1812. I've been to see her lots of times - and on at least two of those occasions the copper (or whatever it is) was removed. But I'll just about guarantee the Navy didn't deliberately spray her with something to make the copper turn green.
Here's an interesting shot of the Charles W. Morgan, sitting at her pier before the most recent restoration: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiT1daeueDMAhWEWSYKHdDYCJkQjRwIBw&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FCharles_W._Morgan_(ship)&psig=AFQjCNEVLFA77f729atYZeci1ZFvQdscpw&ust=1463550868686205 .
And here's what she looked like three or four years ago, when she was hauled out: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwia_uW1ueDMAhUIeSYKHdzFDnQQjRwIBw&url=http%3A%2F%2Fforum.woodenboat.com%2Fshowthread.php%3F109593-Charles-W-Morgan-Restoration-A-Volunteer-s-Perspective-1&psig=AFQjCNEVLFA77f729atYZeci1ZFvQdscpw&ust=1463550868686205 .
It looks to me like the green portion is what was exposed to the air. Here's what she looked like when the Mystic shipwrights got through with her: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjqvYvNueDMAhXHMyYKHcFkDT4QjRwIBw&url=http%3A%2F%2Ferikalinsgreatloopadventure.blogspot.com%2F2013%2F07%2Fhistoric-re-launch-of-charles-w-morgan.html&psig=AFQjCNEVLFA77f729atYZeci1ZFvQdscpw&ust=1463550868686205 .
To my eye that looks like red paint. But I'm not sure.
Several of the old, classic books on ship modeling (E. Armitage McCann, C. Nepean Longridge) tell how to turn a coppered bottom green. The favored method was to wrap it overnight in a cloth soaked in salt water, with a bit of ammonia mixed in.
The old master marine artists sometimes showed ships' bottoms as an orangish brown (they didn't have copper paint in their palettes), and sometimes verdigris green. Ditto Donald McNarry, who, for my money, was one of the finest ship modelers ever.
There is no single right or wrong answer to this problem. And plenty of room for the individual modeler's judgment and personal taste.
On another subject, I'm afraid Ernietheviking got ripped off by a HECEPOB (Hideously Expensive Continental European Plank-On-Bulkhead) kit manufacturer. Several of those firms have released Victory kits, and all of them are awful. (The one really nice wood version of the ship, from what I can tell, is the one from the British firm Caldercraft, aka Jotika. It's on 1/72 scale, and it costs well over $1,000. And even it doesn't get some significant details right. No manufacturer, for instance, has reproduced the five-sided "anchor stock" planking of the wales. None, that is, except Heller and Revell. (The planking on the ship now isn't authentic. The wales are made up of straight boards, which are fastened on top of a layer of "common plank." Financial considerations, I assume. The wales originally were enormous chunks of timber fastened directly to the ship's frames.) In terms of resemblance to the actual ship, there's just no way any HECEPOB product can even approach the Heller Victory or, for that matter, the Revell Constitution.
I certainly wouldn't recommend following a HECEPOB rigging plan. There are several more reliable ones in print. My favorite, as a guide to rigging a model, is Longridge's Anatomy of Nelson's Ships. It contains both a fine rigging plan by George Campbell and Longridge's verbal description of how each individual line leads.
I think the word Ernietheviking was looking for in his comment on deck structure is "caulk." It starts out a very dark grey, and lightens a bit as it ages. My personal favorite trick for representing it is to run a fairly hard pencil around each plank before I lay it. That makes a super-thin, dark grey line that will never disappear, no matter how much the deck is scraped or sanded.