I am about 90 per cent done with my WNW Sopwith Triplane and like you, am doing scheme E and used Humbrol #10 brown slightly lightened with some semi gloss white.
I'm a brush painter but was fortunate to have an old tin of Humbrol 10 ( from the days when Humbrol enamels brushed like a charm). The model looks great with Humbrol 10. I use a blend of Pollyscale Flat and Satin finishes to give the model a suitable doped sheen and the end result is really nice.
Two build issues to beware of - as with the WnW Sopwith Pup, the fuselage with the cockpit tub installed, will not allow a flush fit with the lower wing. The cockpit tub protrudes too low. You have to shave off a good slice of the under cockpit tub assembly to get a good fuselage/ wing fit. A Dremel and wet and dry paper are your friends here. Plus lots and lots of test fitting.
The other design flaw is in the upper cockpit coaming. It will not fit between the cabane struts when the fuselage is glued together. You have to leave one side of the upper cockpit tub loose until you install the coaming then glue the sides together from under the coaming. Annoying but fixable.
Enjoy the build!
cheers
Dave Wilson
Gold Coast
Australia