This was supposed to be red (P.vitifolia) however a friend thought it might be the pale form of P.caerulea 'Contance Elliott'. I also have P. caerulea and this is certainly a lot paler in comparison but I'm not sure as I always thought Constance Elliott was pure white. This particular one stays evergreen all year too.
Unfortunately, while I'm rich in many ways, pecuniary abundance does not number amongst them, hence the camera being ummm less than perfect shall we say LOL A closer picture just blurs out completely as the aperture lets in too much light.
If it helps, the filaments have a bright violet ring and are much shorter than those on P. caerulea and the petals much longer. To be honest it may be that its P caerulea grandfilora or a cross species. I dunno...just musing away
Agree from picture that its a caerulea. As its been in uk for about 200 years its become more varied, & new hybrid lists being produced even name some of these as species selections but all a bit unclear for the moment. I have some pics of 2 quite different caerulea:- http://www.passionflow.co.uk/caer1.htm
and one which looks quite like yours at http://www.passionflow.co.uk/caer11.htm