Scott, I believe there's a B-17 group build going on that you may want to hop on board with. Lots of awesome work going on there.
As far as your question, I'm sure someone will come along with much more solid knowledge, but I know that 8th AAF fighters (P-51B, P-47, etc) used an olive drab over neutral gray paint scheme, and I assume it would be the same for the bomber fleet.
Tamiya's Olive Green (XF-58) is a passable olive drab...maybe a touch on the green side, but it's what they recommended with their P-51B. They also make a pretty dead-on neutral gray (XF-53).
For the interior, Tamiya doesn't make an exact match for the interior green/green zinc chromate used by the U.S. during the war. I'm at work so I don't have any instructions in front of me, but I believe Tamiya calls for mixing Yellow Green (XF-4 - which is pretty much a ringer for yellow zinc chromate) with Flat Black (XF-1). Not 100% certain about the black, but that's how interior green was mixed during the war, so it would make sense.
Good luck with the build!
On the Bench: 1/32 Trumpeter P-47 | 1/32 Hasegawa Bf 109G | 1/144 Eduard MiG-21MF x2
On Deck: 1/350 HMS Dreadnought
Blog/Completed Builds: doogsmodels.com