Hi Tony,
I am not a Be star expert but I would have expected the continuum to be that of the corresponding B star ie a typical hot star spectrum rising towards the blue end. On that basis the flat spectra and that one which dips down at the blue end look strange to me. The stars may be reddened by interstellar extinction though I suppose. For a more experienced view you could ask on the ARAS forum.
Cheers
Robin