Passiflora caerulea question - hardy in Zone 7b?

My daughter is looking at a passi that has purple blooms. It is identified on the tag as Passiflora caerulea, Blue Passion Flower. This definitely does not have blue blooms but dark purple. Is this the same variety? Is it mislabeled? Has anyone found it to be hardy in zone 7b?

Thanks for any help. She'd really like to have this one, but I don't want to see it just die next winter.

Karen