Hi!
The project to build the G.4 in italian colors is really welcomed!
I have to add some comments to the ones above. The G.4 used by "Aviazione del Regio Esercito" were built under license by AER of Orbassano (near Turin). 51 examples were built and, of course, no blue french fittings. They had only red and green section under the wings and tricolor on rudders only on the outer side. Your idea to paint cowlings and wheels with our national colors is a fancy thing, but without any photo proof. The CDL was really near to white, you can see it in the photos. Humbrol 41 "Ivory white" is a good option.
The blue and white cockpit of the Balilla posted above was something of "special colors" applied only on the two a/c's donated by the Commerce Chamber of Genoa to Locatelli and Palli in a great ceremony. For a courious coincidence, they are the only Balillas survived until our days, one restored and held in Bergamo and the second held by Caproni's Museum in Trento, waiting for a decent restoration.
Hope useful!
Roberto