I did one of these a while back, in ESB weathering [MEDIA=imgur]NRH8FCO[/MEDIA]
My colors were Rustoleum French Blue (top coat), Wildflower Blue (chipped paint underlayer), and Brilliant Blue (cheeks).
I really liked how the French Blue topcoat came out, I feel it matches that greyish blue pretty well, so definitely consider that one. The Brilliant Blue cheeks were quite a bit more saturated than I wanted though and I'd choose something else if I did it again. If you're going for the purely two-tone cartoon styling then the Wildflower Blue i used as the underlayer might work for the cheeks, it was pretty much a shaded version of the French Blue top layer, but you may be able to find something else even closer though.
All are gloss colors though so you'll have to clearcoat flat.