DT240's do fit on a Sram Red cassette, However at the moment the 190 cassette body does not. So your only option at the minute is to use a Dura Ace cassette. I've been told that DT will be bringing out a compatible body shortly (but when exactly I don't know).
Don't be concerned with using a DA cassette, nearly everybody I know who runs Red uses a DA cassette and it runs quieter than the Red.