I agree with Ed that 26270 is exactly the right color in full
size. But I believe that is way too dark on a scale model.
Those who "lighten with xx%" may get it exactly, once, but I always
want to be able to go back and touch up, so I want to keep using a
bottle off the shelf.
From the Testors Model Master line, I like the Dark Ghost Grey color for modern Haze Grey.
And Gunship Grey for decks.
But that's a personal opinion.
Rick