If you like the willow green your in luck... their are lots of "Low key" colors like that..
Lincoln makes one, Audi makes a few, SUrbru makes a couple, and Toyota prius and rav 4 have a nice version.. its basically an updated version of old GM frost green... so very nice with matte black... I am very very very interested in these colors as well, something differentiated, muted from afar but 100% rock star when you get up on it.. very fine metallic and tons of clear perhaps a pearl... it can be done... I am convinced.. My builder gave me some sample chip sets to review... I can take a pic of a few if your interested and PM to you..
I think the one I have is the Subaru version, I also have some charcoal metallic that was going to go with it on a firebird project I abandoned a few years ago.
1971 Camaro 427 in waiting
1988 C1500 Daily Driver
1955 Bel Air, blown BBC street car