The paint colour was Olive Drab, a green with a hint of brown. Sorry I haven't got the paint number to hand, but this colour 'weathered' so much, especially in Europe, that the shades changed dramatically, from an olive green, to almost a pure 'earth', or tan brown. Note also that, from February 1944, 'natural metal' (silver) finish was predominant. There are at least two books on the subject of nose art, with many good colour shots of WW2 'girlie' art portrayed.
As catch said, a look in the modelling section might find some pics of WW2 bomber models. Somewhere, there's one of mine in the colour you want, a B26 Marauder.