The most common question I have had since I began the Dominion Building over a year ago is "what did you use or how did you get the patina on your roof?" I even had one person ask if I was using "reindeer piss", he was joking of course.
I feel like everyone thinks I am using some kind of secret formula, but I guess I come forward and revile the smoke and mirrors I use to create the magic. So here it goes . . .
I just mixed three colors of paint!
Kind of disappointing huh? Now here comes the real disappointing part, I don't know what the exact mixture is! My guess is 1/2 green, 1/4 blue and 1/4 white, the reason I don't know is I just kept adding blue or white to the green till it felt right. The key is the blue and I would add it first, then lighten it up with the white.
Now here comes the next trick to making it look real. Once you have the paint down and you have given it ample time to cure, attack it with a very liberal coat of india ink/alcohol, but do it fast and then don't touch it because the alcohol will wash away the paint. When it dries you can add further coats if needed but the first is good enough, I will usually touch up spots and add shadowing later. Then after it is dry add highlights and some texture by dry brushing with white paint. But remember you NEED to weather it for it to look right, just the paint mix alone wont work.
But thats about it, sorry if I disappointed you. If you still have further questions please ask me and I will try to answer it.
These are the exact paint colors I used to make the patina and the resulting color (I think my mix could use a little more blue), any other brand should work just fine as well.