the Baron
Why not, indeed?
First, if you want to go quasi-historical, large bombers used both 'standard' lozenge patterns...which tended toward darker shades...or similar 'hex' pattern in a variety of tones. You could scale up either for your He177 by using the next scale up from the model, i.e. 1/48 decals for a 1/72 kit.
Having both decaled and hand-painted a number of lozenge schemes, decals are incredibly easier. But if you want to go with painting, are you talking brush-painting, or masking and spraying?
If you're brush-painting, there's a slightly easier way than masking. But if you're air-brushushing, it's basically a question of making a template for each color (or a section thereof, like the repeating pattern), laying it out against some straight guideline (panel line, leading edge or light pencil line), and spray...wait to dry...move or switch templates...then 'rinse and repeat' as necessary.
It's not particularly difficult, but it is time-consuming in a major way. Also, be prepared to do touch-ups by hand with a brush, because tiny gaps are nearly unavoidable.
Just a personal opinion, as an aside...I think a 'night bomber' hex pattern on a 177 would look cool as ***k. Neat project idea! 
Cheers 