What, specifically are you painting? top side (hood, fenders) or underside?
I bet you have a difficult time getting a definitive answer to that one. If you have something to look at then I'd spray out some test panels and get it as close as you can.If you have nothing to look at but are going to be somewhere where you'll see some cars like what you want then bring your test panels with you for comparison (I bet you find quite a difference between cars). Your local PBE Jobber (Paint Body & Equipment) has these nice 5"X6" clear Mylar cards that are made for just this sort of thing. Their nice and flexible and soft so you can lay them right on a finished car with no risk of damage, and when you spray them they come with a paddle that has pins to hold the sheets in place while spraying too. Also when your done spraying them out. you dont need to clear them to see what a color (not in your case, obviously) looks like under clear, just flip it over and its near as good as clearcoat. If I want the real deal I still clear them though. Also keep in mind that if your thinking of going strait black with flattner in it, you may want to consider a low gloss clear on top, as flat black, or any other flat color will begin to fade and "chalk" fairly soon after exposure to UV light and if you get wax on it at all, your screwed cause it don't come off of just flat paint, low gloss clear is more forgiving. Remember that if there's little to compare it to for "correctness" for you, then whats to say that what others will use as the "standard" is correct also. Even a 36 year old all origional car has some fade. when I get to my shop I'll post the name of the test panels that I use to make it easy to ask for them if you choose to go that root. Hope this helps, Jeff.