I would imagine it would go the same way as other interwar airforces - non camo schemes but with a sort of 'brand'. Eg the RAF with whitish-grey, small splashes of colour to denote units etc. Or the USAAF - bright blue and yellow. Obviously these are not the only schemes, and I suspect I make huge exaggerations.
On the issue of roundels, I'd imagine they'd remain the same, a la the modern luftwaffe (is it still called that?), which still sports the ww1 style maltese cross.
Morris