Thanks DtD though I have to confess that after debate with (meaning advice from) LAF gaming buddies (Malamute, Dr De’Ath, Elk101 and OshiroMT) I have added more paint!
Essentially a wash of dilute 60% Flat Earth / 40% Yellow Green that was worked especially heavily into the run points, corners and lower courses, then the highlight colour very lightly drybrushed to the tops, upper courses and edges.
A very good choice, breaks the monotony and helps the eye to jump here and there and enjoy little details, your structure has too many to offer!
Eager to see you finishing the vegetation! Cheers!
P.S. And, of course, all this procedure is a very useful tutorial, thanks!